Diagnosis. Protoconch reticulately sculptured. Teleoconch traversed by low radial riblets with shallowly punctate summits. Periostracum buff, spinose at summits of radials, spines emerging from punctations. Radula typical of family. Copulatory organ associated with right cephalic tentacle, usually branching off inner edge. No epipodial tentacles. Eyes present or absent.
Remarks. Coccopigya species differ most obviously from species of Cocculina, Fedikovella and Teuthirostria in lacking epipodial tentacles, and from species of Cocculina (s. str.?) and Fedikovella in having a prominent copulatory organ on the right cephalic tentacle. They differ further from the type species of Fedikovella and Teuthirostria in having predominantly radial instead of reticulate teleoconch sculpture, and in having reticulately instead of concentrically sculptured or smooth protoconchs. The periostracum is more strongly developed than in any other cocculinid (or pseudococculinid) genus, and the presence of periostracal spines is unique to the family.
The periostracal spines are secreted independently from the rest of the periostracum at glandular sites on the mantle edge, and are implanted fully formed at the shell periphery in notches that coincide with the ends of the radial riblets. Sections reveal many thinwalled, longitudinal tubules, none of which appear to communicate with the exterior. The function of the periostracal spines is unknown. Although a spiney periostracum may provide camouflage in shallow water species, this function seems to be unnecessary in deepsea forms. Spines seem unlikely to inhibit settlement of epizoites because there were no obvious epizoites on any of the co-occuring cocculinids and pseudococculinids with smooth periostraca examined during the present study.
Dall (1889, p. 348) considered that of the seven specimens of C. spingera sent to him by Jeffreys, four were males and three were females, and concluded that cocculinids are bisexual. However, these specimens were very immature (length 1.5-2.0 mm) so it seems likely that the copulatory organ was underdeveloped or simply overlooked in the specimens he regarded as females, or that more than one species was present. So far as is known, all cocculinids (and pseudococculinids) are simultaneous hermaphrodites (Thiele 1903B), and the copulatory organ is present in all individuals. As confirmed by an animal reconstituted from a dried syntype (BMNH 1885 : 11 : 5 :4558-4567), DalPs (1889, p. 349, pi. 31, fig. 7, 8) description and illustration of the copulatory organ of C spinigera is highly inaccurate. The species illustrated as C spinigera by Abbot (1974, fig. 198) and as C. cf. spinigera by Bandel (1982, fig. 27A, 77: 3, 80B; pl. 8, fig. 3, 6, 8) do not represent this species and are probably lepetids.