174 YERMETUS. 



Y. FLAVESCENS, Carp. PI. 48, fig. 18. 



" Shell externally closely allied to V. subcancellatus, from 

 which it is principally known by the smaller size and stronger 

 sculpture. Internally it most resembles V. cochlidium, from 

 which it may be distinguished by the absence of keels on the 

 upper lamina through a large part of the length ; and by the 

 general absence of the third plait, which, when it appears, is 

 like another fold of the lower lamina in the same direction." 

 MORCH. 



Sicily. 

 Section ALETES, Carpenter, 1851. 



" The operculum seems to me only different from that of 

 Vermetus in size, in consequence of the larger calibre of the 

 shell. The variety of Vermetus conic us, Dillw., would be 

 referable to this group, if I had not seen one and the same 

 specimen successively in the different whorls change from 

 Vermetus (Petaloconchus) to Thylacodes, and ultimately to 

 Aletes." MORCH. Yet Mo'rch himself admits these subdivisions 

 and the distinction of species by small differences in the 

 internal shell. 



Y. CENTIQUADRUS, Valenc. PI. 49, fig. 35; PL 50, figs. 36-40. 



Laterally attached, spirally twisted, earlier whorls rather 

 narrow, rapidly increasing, the last wide, spread out and com- 

 pressed at the margin ; light yellowish brown, with obscure 

 narrow lines, earlier whorls dark brown, the interstices of the 

 lirae impressed punctate. 



Panama to Gulf of California. 



" The first whorls are of a dark brown color and strongly 

 sculptured with longitudinal linie and transverse rugae exceed- 

 ingty like V. contortus, Carp., which I suppose to be only a form 

 of this shell, judging from analogy with V. conic us, Dillw. The 

 columella shows one exceedingly feeble median lira, scarcely to 

 be seen except in a very favorable light, and two very conspicu- 

 ous lateral lirae which seem to answer to the laminae in V. 

 macrophragma, but they must perhaps be more properly re- 

 garded as the margins of a thin layer covering all the interior 

 of the whorls, except the larger median part of the columella, 

 which shows a slight difference in color." Animal violaceous, 



