CYCLOPHORUS.—MEGALOMASTOMA. 9 
Central America, in Colombia south of the Isthmus of Panama, or Ecuador, viz. :— 
Marmato on the river Cauca, 54° N. lat. (Bland), Quito and Agua Rica in Ecuador 
(Paz and Martinez), Santa Elena>*7 near Guayaquil (Cuming), Salanga, north of 
Guayaquil (Jay °). 
Cyclophorus (?) purus. 
Cyclostoma purum, Forbes, P. Z. S. 1850, p. 56, t. 9. fig. 9* (copied in Martini & Chemnitz, Syst. 
Conch.-Cab. ed. 2, Cyclostoma, no. 226, p. 245, t. 32. figg. 14, 15). 
Cyclophorus purus, Pfr. Monogr. Pneum. Vivent. 1. p. 93°; 
Conch. Icon. xiii., Cyclophorus, t.7. fig. 28°. 
Gray, Cat. Phaneropn. p. 65°; Reeve, 
Precise locality unknown!. It was found by Captain Kellett and Lieut. Wood, 
during the surveying voyages of the ‘ Herald’ and ‘ Pandora’ on the western coast of 
America, somewhere between Ecuador and Vancouver Island; and it has been there- 
fore ascribed to Central America‘. But nobody has again met with it. The nearest 
allied species is C. cwmingi, Sow., from the island of Tumaco, on the borders of Ecuador 
and Colombia; and perhaps C. purus may be only a variety of it (cf. Pfr. Monogr. 
Pneum. Vivent. iii. p. 73). 
MEGALOMASTOMA. 
Megalomastoma, Guilding, in Swainson’s Malac. p. 186 (1840). 
Shell elongated, pupiform. 
truncated. 
Operculum as in Cyclophorus. ‘Tip of the shell often 
Subgen. Tomocycius, Crosse & Fischer. 
Tomocyclus, Crosse & Fischer, in Journ. de Conch. xx. p. 76 (1872). 
Peristoma duplex, externum ad insertionem excisum. 
This subgenus is contined to Central America. 
Sculptura. Basis. Peristoma.. Long. ee xel. 
: mm. mm. 
gealei, Cr. § Fisch. ...... arcuatim costulata. | funiculato-carinata. | dilatatum, anguste et; 39-43 | 114-124 
flexuose excisum. 
simulacrum, Morel. ...... sublevis. Ra latiuscule emargi- 30-45 9-11 
natum, appressum. 
, var. cobanense, Sow. 9 . ss 20-28 73-9 
, var. gracilius ....... _ ss 3 380 5 
guatemalense, Pfr. ...... striatula. compressa nec cari- | perangustum, exci- 24 8 
nata. sum. 
BIOL. CENTR.-AMER., Terr. and Fluviat. Mollusca, May 1890. 
