INSTITUTE OF SCIENCE, PHILADELPHIA. 243 



a synonym of Chicorciis Moiitfort (i8io),and neither in its contents nor in Per- 

 ry's diagnosis has any partcular apph'cation to the group designated Pteronohts 

 by Swainson, though it is possible that one out of the ten species Perry illus- 

 trates may belong to Ptero7iotiis. On the other hand, a swarm of names 

 simultaneously proposed by Jousseaume (1880) are available if, as is doubtless 

 the case, we have to give up Pteronotits ; to say nothing of several others 

 proposed by Bayle (1884). Among these it is difficult to know which to 

 select. It is probable that, for the American s^tc\&s, Pteropiirp7ira , originally 

 founded on Mjirex niacropterus Deshayes, is the most applicable, as they are 

 most nearly related to one another and less likely to be closely allied to the 

 Indopacific forms. The extension o'i Pierop7irpm-a over the whole of the sub- 

 generic group Pteronotns is a question requiring more attention than the 

 writer can at present give it, to be adequately discussed. 



If the recurvation of the tip of the varices be regarded as a character 

 worthy of sectional separation, as has been claimed by Bayle, an opinion the 

 writer is hardly ready to accept, the species M. textilis Gabb will be referable 

 to the section Triremis Bayle. For the present it is probable that it will do 

 very well under the designation of Miirex {PteropurpJird) textilis. 



Genus TROPHON Montfort. 



Subgenus Aspella Morch. 



Aspella (Morch) Dall, Rep. Blake Gastr., p. 206, 18S9. 

 Poweria Monterosato non Bonaparte. - 



Trophon (Aspella) engonatus n. s. 

 Plate 13, figure 6 a. 



Pliocene beds of Florida at Shell Creek, Willcox. 



Shell elevated, with prominent sculpture and eight whorls ; nucleus small, 

 smooth, of two and a quarter whorls; remaining whorls each with three princi- 

 pal and three minor varices, which are thin, sharp and spinose at the intersec- 

 tion of the spiral ribs, especially at the shoulder; whole surface covered with a 

 thin limy coat, evenly and finely spirally striate, but this coating is usually 

 partly worn off, being very perishable ; other spiral sculpture of three (on the 

 last whorl 6) sharp, narrow, elevated spiral riblets which overrun the varices, 

 and (especially on the major varices) tend to form spines at the intersection ; 

 the spiral rib at the shoulder is especially prominent and tends to turriculate 

 the whorls; whorls full, rounded under the sculpture; aperture ovate; canal 

 long, open, narrow, much recurved ; outer lip with a few coarse lirae within 

 in the adult. Alt. 28; max. diam. 12 mm. 



This species closely resembles, when adult, the recent Aspella obelisctis 

 A. Adams, but differs from it by the narrowness and sharpness of the varices 

 and spirals, and by the spinous projections at the shoulder. The internal liras 

 of the outer lip are fewer and coarser than in A. obelisctis and the varices are 

 not continuous up the spire with such unvarying precision in the fossil as in 



