178 CHLOROSTOMA. 



is not notably different from that of C. reticulatum ; the columella 

 and inside of the umbilicus are either green or white. 



Alt. 8-9, diam. 12 mill. 

 Taboga, C. A. (C. B. Ad.) ; Cape St. Lucas and La Paz, L. Gal 



Trochus coronulatus C. B. AD., Cat. Shells Panama, p. 191, 317 

 (1852). Omphalius turbinatus PEASP:, Am. Journ. Conch., v, p. 84, 

 t. 8, f. 15. 



This little species may be recognized by the close microscopically 

 striated surface and the several keels of the last whorl, the upper 

 one nodose. It is one of those species where the sculpture is very 

 mutable because almost any one of the strife is likely to become 

 magnified into a strong rib or carina. Clanculus plebejus is precisely 

 comparable to this form in this respect. Chlorostoma semigranosa 

 AD. is allied to this form but is much more coarsely lirate. Adams 

 gives for alt. "55, diam. '72 inch. 



Omphalius turbinatus is the adult of this species, as I have satis- 

 fied myself by an examination of the type specimens. The follow- 

 ing is Pease's description : 



Var. TURBINATUM Pease. PI. 24, fig. 90. 



Shell openly and deeply umbilicate, somewhat depressly turbinate, 

 thick, solid ; whorls angulate above, the last obsoletely angulate 

 at the periphery, encircled by small slightly nodulous ridges, inter- 

 stices elevately striate ; base convex ; smooth or obsoletely ridged, at 

 the umbilical region smooth ; columella at base nodosely dentate, 

 and terminating in a very slightly elevated tooth (not grooved). 

 Yellowish or whitish, radiately obliquely marked with reddish-brown 

 interrupted stripes, the base marbled with reddish-brown. Umbilicus 

 and columella sea green, operculum bright yellow. 



Alt. 13, diam. 18 mill. 



La Paz, Gulf of California. 



C. SEMIGRANOSUM A. Adams. PI. 29, figs. 65-67. 



Shell umbilicate, conical, about the size and shape of C. reticu- 

 latum Wood ; whorls of the spire but slightly convex, the sutures 

 linear, not impressed ; coloration consisting of radiating irregular 

 divaricating flames, fine lines and dots of umber almost covering a 

 whitish ground, sometimes entirely covering it except for small dots 

 of white on the line; whorls 5 to 6, encircled by very numerous 

 close irregularly crenulated spiral line, about 10 to 12 on the last 

 whorl above the periphery, the interstices narrow, spirally striate 



