What's A Rice Olive, Anyway?

By Harry G. Lee

    Each of these looks like an Olivella (sensu lato) but at first inspection has no pillar modification or fasciolar structure (see "P" and "F" in Fig. 5), which distinguishes this triad from any member of the generic group (sensu lato) known from the Americas (Olsson, 1956), Australia (Wilson, 1994), or in the largest assortment of world-wide species-level taxa (105 in toto) treated in the literature (Kaicher, 1987).

    Let's consider the largest shell first. Sir Joseph Verco named Olivella (?) adiorygma (1909; p. 338. pl. 25, figs. 3,4; our Fig. 2) from 17 fathoms, Backstairs Passage, South Australia; the type is 5.2 mm in length. Cotton and Godfrey (1932; p. 54) designated it the type of Ramoliva, new genus.  Wenz (1943; p. 1272, Abb 3621) synonymized Ramoliva with Olivellopsis Thiele, 1929 (p. 333; fig. 384), but the type (by original designation) of the latter generic unit, Olivella (Callanax) simplex Pease, 1868 was first described thus: "Long. 4 1/2, diam. 2 mill. ... Paumotus ... Shell somewhat fusiform, truncate at base, smooth, white; whorls four, marginated and slightly angulate at sutures; spire somewhat produced; outer lip simple, smooth within; aperture wide; columella slightly curved and callous.  The generic characters of the above are doubtful.  It may prove the type of a new genus.  If correct, it is the first species of Olivella described from Polynesia" [p. 281; pl. 23, fig. 24; our Fig. 3].  The Pease species, although poorly illustrated, has a different profile and suture than the Verco species. Thiele (1929), in defining Olivellopsis, wrote: "Schale sehr klein, farblos, Naht mehr angedrückt, Spindelschwiele ohne untere Falte." Translated by Jochen Gerber on August 24, 2004: "Shell very small, colorless, suture more appressed [than Belloliva Peile, 1922; see below], columellar callus without lower fold."  Just what "more appressed" means is critical to the understanding of this taxon; is the suture channelled or not? Since the identity of the Pease species (and thus Olivellopsis Thiele, 1929) was not at all clear, it was imperative to get an authentic specimen if this problem was to be worked out. Thus I searched my library for leads on the location of Pease's collection and promptly found a bio-bibliography of Pease (Kay and Clench, 1975), which indicated that "a great many of Pease's species are in the Pease collection of the Museum of Comparative Zoology [MCZ], Harvard University; others are in the British Museum (Natural History) and in the Academy of Natural Sciences of Philadelphia [ANSP]."  I wrote Adam Baldinger at the MCZ, who replied almost immediately that in a more detailed report on the Pease collections (Johnson, 1994; p. 24) located Pease's Olivella simplex at the ANSP and designated a lectotype and paralectotype. Collections Manager Paul Callomon kindly provided me with a photograph of the lectotype (ANSP 28969; Fig. 4).  Clearly Olivella simplex Pease, 1868 is not a close relative of Olivella adiorygma Verco, 1909. We shall postpone discussion of O. simplex temporarily.

    Barry Wilson (1994; p. 132) examined the type specimen of Olivella (?) adiorygma Verco and concluded it "... may be a synonym of [Cupidoliva] nympha" (Adams and Angas, 1864) thus suggesting synonymy not only the two species, but the genera Ramoliva and Cupidoliva Iredale (1924; pp. 183, 259), of which O. nympha is the type. Fig. 5 is a scan of a syntype of C. nympha (BMNH 1870.10.26.92; whitened with magnesium oxide) from Kaicher (1987; card 5038). As the illustrations indicate, there is very little similarity between the two species in suture, pillar and fasciolar structure.  Verco (1909) stated "It [O. (?) adiorygma] differs from Olivella in the absence of a canaliculate suture [our highlight], and from the Volutidae in its smooth columella.  Its generic location is unknown to me."  The lateral view (Verco's fig. 4, but also visible in his fig. 3 - in our Fig. 2) also shows an apicad progression of the suture over the last quarter whorl, which is apparent in all four of my Hopetoun specimens as well.  These characters are inconsistent with Olivella nympha Adams and Angas, 1864, and thus with Cupidoliva Iredale, 1924. I believe the middle shell in Fig. 1, from Hopetoun, is Ramoliva adiorygma (Verco, 1909) and conclude, as Verco hinted, that this species (and therefore its genus) is not closely related to Olivella (sensu lato).

    In the same work Verco also named a somewhat similar shell Olivella solidula (Ibid. p. 39; figs. 7, 8; our Fig. 6).  It was taken from Encounter Bay, South Australia, quite near the type locality of O. adiorygma and about 800 miles east of Hopetoun.  He characterized it as "solid, shining white, smooth, obliquely elongate-oval. Apex blunt, four whorls, sloping convex, suture well channelled.  Aperture oval, contracting gradually to a linear gutter posteriorly, widely-open in front, and notched; outer lip simple, smooth; inner lip is a narrow, thick glaze over the base to the suture, slightly spreading over the columella .... 6 mm. (by) ... 2.3 mm."  As seen in Fig. 6, the shell has relatively narrowly-channeled sutures and no evident fasciolar or pillar sculpture.  The absence of the latter features contrasts with Olivella [now Belloliva] exquisita Angas, 1871, which Verco wrote "it closely resembles [but differs] in being smaller, narrower and pure-white." A solitary specimen which matched the type illustration of Olivella solidula was found in my lot of Hopetoun Ramoliva adiorygma. Most regrettably, this shell was accidentally crushed in preparation for scanning. Our Fig. 7 is a 8.2 mm B. exquisita in my collection taken near shore, Cogee Bay, NSW, Australia.  An image of another specimen whitened with magnesium oxide (Kaicher, 1987; card 4966; Fig. 8) more clearly demonstrates the pillar and fasciolar features, which are absent from Olivella solidula.

    Olivella solidula was not treated in Wilson (1994), but he synonymized Olivellopsis Thiele with Belloliva Peile, 1922 [type Olivella brazieri Angas, 1877; Cotton, 1955, fig. 9; our Fig. 9], which, like Belloliva exquisita and B. triticea (Duclos, 1835), has a twisted pillar and conspicuous fasciolar sculpture. In fact, O. solidula, particularly a stout form illustrated by Cotton (1955; fig. 11; our Fig. 10), bears a closer resemblance to Olivellopsis simplex (Pease, 1868), Fig. 4, than either does to Belloliva brazieri.  Olivella solidula and Olivellopsis simplex may well be congeneric. The two smaller shells in Fig. 1 resemble both these species.  Upon close examination of its dorsal aspect, each of the smaller Fig. 1 shells has a very faint fasciolar groove/ridge which meets the outer lip just behind its anterior extremity (as was the case with the destroyed Hopetoun shell). Although Paul Callomon (personal comm., Sept. 17, 2004) could see no such feature in the Pease lectotype, in this cosmopolitan and apparently natural group it is a very subtle character which may be effaced in older or abraded shells. If this feature proves consistent from one form to the next, and in consideration of the channeled sutures of these shells, this group of four putative taxa are likely very close to or in the Olivella (sensu lato).

    Based on the findings above, the diagnosis of these three shells in Fig 1 is (left to right): Olivellopsis species A [Olivellinae?; first Atlantic and New World record?], Ramoliva adiorygma (Verco, 1909) [Columbellidae?], Olivellopsis species B [Olivellinae?; first Indian Ocean record?]. Needless to say, I appeal to readers to be on the lookout for other material comparable to these three odd "Rice Olives" so that we can better appreciate the systematic relationships of each.

Acknowledgements:  I am indebted to Adam Baldinger (MCZ) for provision of the Johnson reference, Paul Callomon (ANSP) for examining and photographing the lectotype of Olivella simplex, Bill Frank (Jacksonville, FL, USA) for assistance in the preparation of the figures and layout, Jochen Gerber (Field Museum, Chicago, USA) for translation of the Thiele passage from German, Dr. Patty Jansen (Lindfield, NSW, Australia) for the provision of critical portions of the Verco monograph, and Richard E. Petit (North Myrtle Beach, SC, USA) for access to Pease's original paper.

Literature cited:

Cotton, B. C., 1955. Family Olividae. Royal Soc. South Austral. Mal. Section, pamphlet no. 6. 3 pp. (not paginated) + 1 pl. May 30.

Cotton, B. C. and F. K. Godfrey, 1932. South Australian shells. South Australian Naturalist 13: 35-86.

Iredale, T., 1924.  Results from Roy Bell's molluscan collections. Proc. Linnean Soc. New South Wales 49: 179-278, pls. 33, 34. Oct. 24.

Johnson, R. I., 1994.  Types of shelled Indo-Pacific mollusks described by William Harper Pease (1824-71). Bull. Mus. Comp. Zoology 154(1): 1-61.

** Kaicher, S. D., 1987.  Olividae part II no. 49 [card nos. 4942 through 5046]. Card catalogue of world-wide shells. Published privately, St. Petersburg, Florida. Aug.

Kay, E. A. and W. J Clench, 1975.  A biobibliography of William Harper Pease, malacologist of Polynesia.  Nemouria. Occasional papers of the Delaware Museum of Natural History 16: 1-50. Dec. 30.

Olsson, A. A., 1956.  Studies on the genus Olivella. Proc. Acad. Nat. Sci. 108: 155-225 + pls. 8-16.

Pease, W. H., 1868.  Descriptions of sixty-five new species of marine Gasteropodae, inhabiting Polynesia. American Journal of Conchology 3: 271-297, pls. 23, 24.

Rosenberg, G. and R. E. Petit, 2003.  Kaicher’s card catalogue of world-wide shells: a collation with discussion of species named therein. The Nautilus 117(4): 99-120. Dec. 23.

Thiele, J. 1929-1931. Handbuch der Systematischen Weichtierkunde. Bd 1. Jena: Gustav Fischer, vi + 778 pp.

Verco, J., 1909. Notes on South Australian marine mollusca with descriptions of new species, part XII. Trans. Roy. Soc. S. Australia 33: 293-342.

Wenz, W., 1938-1944. Handbuch der Paläzoologie, herausgegeben von O.H. Schindewolf. Band 6. Gastropoda: Allgemeiner Teil und Prosobranchia 1-946 + xii; 947-1507-1639 + 1*-10.*