168 STRAMONITA. 



in the same work is cited bj- Conrad as the type of his P. nebn- 

 losa (fig. 94) ; P. NuttalU, Conrad (fig. 109), from Fayal, is again 

 the same form. P. viverratoides, d'Orb. (fig. 103), from the 

 Canary Islands, is so completely dissimilar to the typical hsema- 

 Ktoma that it is no wonder it was described and figured as a dis- 

 tinct species ; yet it is only a variation of the Floridana type — 

 a variation which is quite abundant among West Indian speci- 

 mens of the latter, and it is connected with hsewastoma by an 

 unbroken series of gradations. 



Bifierialis, Blainv. PL 50, figs. 9t, 99. 102.* 



In some of the shells thus named the aperture is white, but 

 usually' it is orange-colored, with an unmistakable recurrence to 

 the typical P. hsemoMomo. It occurs from Southern California 

 to Panama very plentifully. Other names of this group are 

 iinifascialis, Lam. (fig. 102), hiematuro, Val., macrosfoma, Kiis- 

 ter (fig. 99), Consul, Mkc; (non Lam.). 



Bicosfalis, Lam. PI. 50, figs. 91, 93. 



P. P. Carpenter jiroposes that this name be reserved for the 

 East Indian forms ; its normal type as well as a specimen deA'oid 

 of tubercles and almost without shoulder, are well represented 

 by Reeve's figures (which I have copied), although the originals 

 of these are from West Cohimbia. 



* SiNUSIGERA. 



Mr. Arthur Adams has identified a Cheletropis with Pvrpvra biserialis, 

 of ■^hich he supposes it to be the larval state fsee nnfc, p- 52). The fol- 

 lowing species of Cheletropis (= Sivungera) have been described : 

 S. CANCELLATA, Orb. (Figured in Keferstein.) PI. 8, figs. 101, 102. 

 S. MICROSCOPIC A, Gray (= Huxleyi, Forbes). PI. 50, fig 88, 

 S. GLABRA, A. Ad. 

 S. TROCHOIDES, A. Ad. 

 S. VITREA, A. Ad. 

 S. CRENiLABRis, Garrett. PI. ."in, fig. 89. 



The arms, four in number, are arranged in a cruciform manner around 

 the head. There are two tentacles, and the eyes, well formed, are situated 

 on the outer side of their bases. Respiratory siphon short, being a simple 

 fold of the mantle. Foot large and very mobile, furnished with a small, 

 thin operculum ; unprovided with a float. 



