LEl'TOTHYRA. 247 



and by Woodward. (PI. <H), figs. 61, 62.) I do not understand 

 the discrepancy between the description of the operculum and De- 

 shaves' figure of it. The main character distinguishing dollunia. 

 from Leptothyra seems to be the peculiar peristome of the former. 

 Fischer savs of it : "peristome continu, epaissi, dilate, except/* sur le 

 bord columellaire ; labre epais, parfois subdouble ou subreflechi. * 



* --I'- # 



Les coquilles de cc groupe ne paraissent pas avoir ete nacrees* 

 Lenr opercule ressemble a celui des Leptothyra, mais lenr ouverture 

 rappelle celle des Liotin." ( Manuel de Conch., p. 812.) 



There are numerous Tertiary species. 



NOTE. The operculum of Leptothyra frequently offers excellent 

 specific characters, just as it does in Turbo and AstraUum ; and at- 

 tention to these will often enable one to readily separate species of 

 which the shells exhibit considerable similarity. 



L. cAiii'KNTKRi Pilsbrv, 1888. PL 39a, figs. 26-29. 



Shell small, globose, very solid, imperforate, spire conic, more or 

 less depressed ; suture moderately impressed ; whorls 5, slightly 

 convex, the last decidedly deflected toward the aperture, encircled 

 by about fifteen subequal spiral lino, separated by interstices about 

 as wide as the ridges ; incremental stria? generally strongly devel. 

 oped, causing the. lira 3 to appear nodose or somewhat irregular, and 

 the interstices to appear pitted; aperture oblique, pearly white 

 within, about half the length of shell ; columella arcuate, base ob" 

 soletely uni- bi- or tri-dentate; color red, ashen or purple. 



Alt. 8, diarn. 8-9 mill. ; dark form alt. 5, diam. 5 mill. 



Cape St. Lucas, L. California to Vancouver Id. 



( Jperculum ('pi. 60, fig. 66) rounded oval ; outside much thinner 

 and less elevated around the margins than that of L. wnguinea, 

 slightly concave in the middle, nearly smooth. 



This is L. cow! 11 eus of Troschel, not Miihlf., L. calif or mem von 

 Martens, not of Philippi, L. sanguineus of Carpenter and authors 

 generally, not of Linn., and var. purpureus Carpenter, (preoc). 



The Californian shells appear to me to be quite distinct from the 

 Mediterranean species ; I have been unable to find, in the numerous 

 specimens of the latter form which I have examined, any trace of 

 the peculiar indentations in the grooves or of the uneven character of 

 the line which are so conspicuous in the California!! species. The 

 lira of L. Carpenteri are generally smaller and more numerous; 

 about five or six are visible on the penultimate whorl ; and those 



