65 



ceeded Leacli in tlie Britisli Museum, and publislied many of 

 Ms predecessor's genera with, due acknowledgment.) Shell 

 nearly always conical, last whorl angular, no umbilicus, 

 columella simple, aperture C[uadrate. I do not see how these 

 shells can be distinguished from Thalotia except by the more 

 elongate form of the latter. The animals of Thalotia have 

 not been examined. In Zizijpliinus the branchial plume is 

 acutely pointed in front, long, tapering like a leaf, and com- 

 posed of one or more rows of short close-set strands. The male 

 organ is a nan-ow white, tough, gently arcuate and subulate fila- 

 ment lining or attached from base to point to one side of the 

 branchial leaf. The orifice of the ovary is placed below the 

 rectum. Eadula central, laminaceous, lanceolate, three parts 

 of the base oval, suddenly wider) tip recurved, sharp, serru- 

 lated on both sides ; lateral teeth on each side five, imbri- 

 cated, and shaped like the half of the central one, the last 

 somewhat different in shape, lateral series of teeth, 60 and 

 upwards on each side, the first by far the stoutest, the base 

 dilated behind, the hook toothed below with tubercles, the 

 remaining teeth slender, with a compressed hook pointed ; 

 in the inner one, toothed below, serrulated on both, sides ; 

 in the middle ones, pectinated on each side ; in the last, 

 obsolete, scape slender, simple, furnished before the base 

 with an external, spur-shaped ; lingual membrane long, 

 linear, transparent (curled ?) Gray, loc. cit. 



Elenchus, Humphrey, 1797 (Museum Calonnianum, 

 Specification of the various articles which compose the mag- 

 nificent museum of natural histoiy collected by M. de 

 Colonne in France. Anonymous, but known to be by Geo. 

 Humphrey, F.L.S.), see Swainson's " Shells and Shell-fish," 

 p. 15. We must accept Swainson as the real author of this 

 genus, as he was the first to define it. It is called Eleuchus 

 and Heleuchus, see Hermannsen, vol. I, p. 416. Swainson 

 says loc. cit., p. 219. These splendid shells, although mostly 

 of a small size, have a brilliancy in the emerald green of 

 their apertures, which is perfectly unrivalled in this family; 

 the basal whorl is convex ; the spire is also produced ; the 

 base of the pillar in some forms an angle, and in others a 

 small but very distinct tooth. The exterior is always smooth. 

 " This beautiful group," he adds in a note, " was well known 

 to Humphrey, whose name imposed near 40 years ago 

 (Swainson was writing in 1835) we have of course retained 

 instead of some others recently given by the French nomen- 

 clators." The group is well defined geographically as well 

 as naturally, for the species are all Australasian, and more 

 common on the south than on the east or west coasts. 



