168 STRAMONITA. 



in the same work is cited by Conrad as the type of his P. nebu- 

 losa (fig. 94) ; P. Nuttalli, Conrad (fig. 109), from Fay al, is again 

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

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

 stoma 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 haemastoma by an 

 unbroken series of gradations. 



Riserialis, Blainv. PI. 50, figs. 97, 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. haemastoma. It occurs from Southern California 

 to Panama very plentifully. Other names of this group are 

 unifascialis, Lam. (fig. 102), hsematura.-, Yah, macrostoma, Kiis- 

 ter (fig. 99), Consul, Mke. (non Lam.). 



Bicostalis, Lam. PL 50, figs. 91, 93. 



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

 East Indian forms ; its normal type as well as a specimen devoid 

 of tubercles and almost without shoulder, are well represented 

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

 of these are from West Columbia. 



* SlNUSIGERA. 



Mr. Arthur Adams has identified a Cheletropi* with Pm-pura biserialis, 

 of which he supposes it to he the larval state (see ante, p. 52). The fol- 

 lowing species of Cheletropis (=-- Sinusifjera) have been described : 

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

 S. MICBOSCOPICA, Gray (= Huxleyi, Forbes). PL 50, fig. 88. 



S. GLABKA, A. Ad. 



S. TROCHOIDE8, A. Ad. 



S. VITBEA, A. Ad. 



S . CRENiLABBis, Garrett. PL 50, 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. 



