GUPPY — ItOLLUSCA OF TRIXIDAD. 
27 
Melampus pus illus Gmelin. 
Voluta pusilla, Gmel. Syst . p. 3436, 
,, triplicata, Donovan , Brit. Shells, iv, pi. 138. 
„ „ Wood , Ind. Test. pi. 29, f. 19. 
Bulimus ovulus, Bruy. 
Auricula ovula, Fer. 
„ nitons, Lam. 
Melampus ovulum, Lowe. 
„ pusillus, Adams. 
„ „ Pfeiffer, Mon. Auric, p. 46. 
Tralia pusilla, Gray . 
An ovate-obconic solid smooth dark-fuscous shining shell 
with three plaits on the inner margin of the aperture, and 
a single internal transverse rib on the outer lip. Length 
(of a fine example) 14, breadth 8 mill. 
Found on the north coast of Trinidad, and in most of the 
West Indian Islands. 
Planorbis Geoffroy 1767. 
Fluviatile Inoperculata with discoid shells, generally 
biconcave, having an aperture without teeth, the peristome 
simple or somewhat expanded with the upper margin 
projecting. 
Planorbis terversanus D’Orbigny. 
D'Orligny , Moll, de Cuba , pi. xiii, f. 20, 23. 
A small discoidal shell generally subdiaphanous with 
whorls flattened above and rather rounded beneath. The 
spire presents a concavity above as well as below. The 
peristome, usually simple, is occasionally expanded in old 
examples, which are often black and thickened. 
Diameter 10 millimetres, height (thickness) 3 mill. 
It is found in small streams among the Laventille Hills, 
and in Naparima. It also exists in Cuba and probably in 
other islands of the West Indies. 
