MUSEUM OF COMPARATIVE ZOOLOGY. 317 



interior white, polished. Lon. of shell, 8.3; of last whorl, 4.4; of last varix, 

 3.1; of aperture, 2.5; max. lat. of last whorl, 6.75; of varix, aperture, and 

 callus taken together, 4.75; of aperture, 2.3 mm. 



Station 290, off Barbados, in 73 fms., sand and shell, bottom temperature 

 71°.0 F. 



This very lovely species does not resemble closely any of those described in 

 the monographs. The form of the varices recalls those of Hoplopteron. In its 

 turbiniform shape it resembles S. pernobilis, the young of which, judging from 

 the apex of the beautifully preserved Fish Commission specimen, have much 

 more solid, hardly alate varices. It most resembles S. Diana Hinds, as figured 

 by Reeve, but in this species, which comes from the Philippines, the alee are 

 situated on a different part of the varix, and are of a distinctly different shape. 



One would think the sharp close-set varices an excellent defence, but the 

 specimen described has been drilled by a carnivorous gastropod. 



Scala centiquadra Murch. 



S. centiquadra Morch, Cat. Scalidas, he. cit., p. 195, pi. xxix. fig. 4, 1876 (ref. excl.), 

 non Malak. Blatt, XXII. p. 145, 1874. 



Habitat. Station 2, in 805 fins., one dead specimen; Bahamas, Rawson; off 

 Hatteras, in 49 fms., U. S. Fish Commission. 



There is no doubt that the species which Mbrch described in 1876, and fig- 

 ured as <S. centiquadra is entirely distinct from the shell figured by Sowerby 

 under the name denticulata. Why Morch should have confounded them does 

 not seem plain, nor why he should have referred to the name denticulata as 

 preoccupied by Montagu, when Montagu's species is a well known West In- 

 dian Rissoina. S. denticulata Sowerby is a good species, and has been obtained 

 at U. S. Fish Commission Stations 2595 and 2596, in 49-63 fms., about twenty 

 miles off the coast of North Carolina. It is striated spirally, but not decussated 

 like & centiquadra. A variety (?) sent by Governor Rawson from the Bahamas 

 shows great irregularity in the varices, of which there are six on the last whorl, 

 two or three of which on each whorl are much stouter than the rest, and 

 rounder than in the typical dentiadata. The others are fainter than the nor- 

 mal, and the sutures are deeper than in the type, which has about twice as many 

 varices. This variety I have named S. bahamensis, but I am not confident that 

 a larger series would not establish it as a good species. 



Scala Pourtalesii Vebeill & Smith. 



Scalaria fourtalesii V. & S., Am. Journ. of Science, pp. 391, 395, Nov., 1880 ; Trans. 

 Conn. Acad., V. p. 527, pi. lvii. fig. 32, 1882. 



Habitat. Off Martha's Vineyard, in 85-115 fms., Verrill; fourteen miles 

 west of Gun Cay, Bahamas, in 351 fms., Dr. Rush: off Sombrero, West In- 

 dies, in 72 fms., Blake Expedition. 



