MUSEUM OF COMPARATIVE ZOOLOGY. 201 



Subgenus PTERONOTUS Swainson. 



This group has been rcgarchid as rather characteristic of the sliores of the 

 Soutliwestcru Pacific Ocean, but we now have several species to add to the 

 Atlantic fauna, where a few were already known. 



Pteronotus macropterus Deshates. 



Murcx macropterus Deshayes, Mag. de Zool., 1841, pi. xxxviii. 

 Pteropurpura macroptera Jousseaume, 1880. Fischer, Man., p. C41, 1884. 



Habitat. U. S. Fish Commission Station 2595, 22 miles E. S. E. from Cape 

 Hatteras, N. C, in 63 fms., sand, bottom temperature 75° F. 



Two living specimens of the abov.e species were obtained by the Albatross. 

 The operculum is as figured by Deshayes in his original paper, the nucleus 

 nearly lateral, but also nearly apical, as in M. rufus and M. pomum, though of 

 course on a smaller scale. This species has had a generic or subgeneric name 

 applied to it, but as for differential characters there are none alleged of a 

 permanent and definite character. 



Pteronotus phaneus n. s. 



Shell ashy white, elongated, thin, six-whorled. Nucleus translucent, smooth, 

 polished, of about one and a half whorls ; whorls slightly convex, appressed to 

 the suture behind them, connected by three continuous fin-like varices which 

 in descending the spire make about half a revolution around it; these varices 

 on the upper whorls were extended backward into a little wing-like point with 

 dentate edges ; on the last whorl the lines of growth indicate that the thin 

 margin was rounded, parallel with the whorl. Transverse sculpture of fine 

 growth-lines, and on the last two whorls at the periphery three short little 

 narrow pinched-up riblets between the varices; spiral sculpture of fine rather 

 faint strioe and wider undulations, hardly visible except on the varices; of these 

 there are nine or ten on the last varix. Aperture elongate-oval, internally 

 white, thickened, smooth; canal rather long, open, bent back. Max. Ion. of 

 shell, 17.0; of last whorl, 13.5; of aperture, 5.0; max. lat. of aperture, 3.0; of 

 shell, 8.0 mm. 



Habitat. U. S. Fish Commission Station 2662, off St. Augustine, Florida, 

 in 434 fms., sand, temperature 43°. 7 F. 



This species agrees more nearly with the Indo-Pacific species by having three 

 inter-varical ribs, while the Atlantic species hitherto known have only one. It 

 is, however, more nearly related to the next species than to any hitherto de- 

 scribed, as far as I have been able to ascertain. The body of the shell is not 

 unlike that of P. cordismei Watson, figured in the Challenger Report, but the 

 present species has none of the semitubular spines which give the Australian 

 shell the look of a Typhis. 



