THE NAUTILUS. 63 



eyes on protuberances at their outer bases; the antarctic forms 

 have long slender tentacles with the eyes about one third the 

 length from the insertion of the tentacle. Behind the true ten- 

 tacles is another pair, shorter and without eyes, probably really 

 belonging to the epipodial series of cirri, but separated by a 

 gap from the other shorter ones behind them. These pseudo- 

 tentacles were figured from life by Couthouy and from a spirit 

 specimen by Strebel, and are not represented in the forms of 

 the northern hemisphere. The males in both groups have a 

 well developed verge behind the right tentacle. This of course 

 disposes of the identity claimed on conchological grounds for 

 the antarctic and northern species like noachina. 



Beginning with those species destitute of props to the septum 

 we have P. cucullata Gould, 1849 ; high, with strong ribs, wide 

 interspaces which may be smooth or radially grooved. It ranges 

 from Kadiak Island to La Paz, Mexico. Nearest to this is P. 

 multistriata Dall, n. sp. with small, slightly alternated, rather 

 close set radial threads. This has generally been associated 

 with cucullata as an extreme variation ; but the very large series 

 I have indicates that it is distinct. It ranges from the Aleutian 

 chain south to San Diego, and the Cortez Bank, Cal. 



P. cooperi Carpenter, 1864, has been received from southeastern 

 Alaska and extends to the Santa Barbara Islands, Cal. It is 

 small, erect and very feebly sculptured. 



P. caryophylla Dall, n. sp. minute, high, cylindro-conic, with 

 strong, even, radial threads, resembles nothing so much as a 

 miniature solitary coral, and has been dredged off San Diego, 

 Cal., in 40 to 80 fathoms. 



P. longifissa Dall, n. sp. is low, narrow, small, with an arcuate 

 back, strong radial threads, very posterior apex, and the slit 

 half as long as the distance from the apex to the anterior margin. 

 It has been found only in 10 fathoms, off Bering Island, Bering 

 Sea. 



The Antarctic species are P. cognata Gould, 1849, from Orange 

 Harbor, Patagonia, which has been often identified as P. 

 noachina, being one of the species with props. P. falklandica 

 A. Adams, 1862, is without them, while P. conica Orbigny, 

 1841, has only the faintest traces of a supporting callus. Both 



