BALL : MOLLUSCA AND BRACHIOPODA. 303 



ated, twisted, almost pervious ; aperture narrow ; outer lip very thiu, sharp, con- 

 cave uear the shoulder, produced in front, modified by the sculpture, but not 

 lirate. Height of (eroded) shell, 30; of last whorl, 21 ; diam. 9 mm. 



U. S. S. "Albatross," stations 33G0, 3374, 3392, and 3415, in 1270 to 1879 

 fathoms. Gulf of Panama to Acapulco, sandy or oozy bottom, ten)peratures SS^.O 

 to 36^4 F. U. S. N. Mus. 123,006. 



This elegant little sliell recalls Boreotrophon in its sculpture. The spirals in 

 some of the specimens are narrower and more numerous than in the type, and 

 in the young the ribs are less sharj) and the color more ashy. 



TROSCHELIA MoRcir. 



Troschelia Morch, Journ. de Concliyl., 1876, 24, p. 370; type, Fusus berniciensis 



King. Not Troschelia Duncan, Euhinidae, 1883. 

 Boreo/usus G. O. Sars, Moll. Reg. Arct. Norv., 1878, p. 278 ; type, /i. berniciensis 



King. 



Shell elongate, fusiform, with a produced recurved canal, a short, rounded- 

 triangular operculum with apical nucleus, slightly sinistrally curved; the radular 

 formula iV + 1 + iV» ^-''^ ^^^p of tiie rhacliidian plate well developed, nearly as 

 long as the base ; animal having the eyes developed. 



Tlialassoplancs Dall, subg. uov. 



Shell short, the canal very short, the operculum straight, elongate, wedge- 

 shaped, the extreme apex slightly turned to the right ; radula (of the type) with 

 tlie formula J + ^ + Jt the rhacliidian plate with the cusp obsolete ; animal blind, 

 male with a small, subcylindric verge, without appendices. Type T. mdrc/iii Dall. 



Troschelia (Thalassoplanes) morchii Dall, n. sp. 



Shell short, stout, with about five whorls, of which two are nuclear, polished, 

 depressed, smooth ; subsequent whorls uniformly sculptured with (l)ctwccn the 

 sutures seven, on the last whorl nine or ten) narrow, similar, flat-topped, elevated 

 ridges, with much wider, equal interspaces, and on the canal seven additional 

 spiral threads ; tiiis sculpture is crossed by numerous (three or four to a milli- 

 meter) equal and equally spaced, flexnous, smaller elevated axial threads, which 

 override the ridges and divide the channels into rectangular spaces ; the whole is 

 covered by a fil)rous, thin, olivaceous pcriostracum ; suture distinct, not chan- 

 nelled; whorls turgid and evenly rounded; aperture nearly equal to the spire, 

 outer lip tliin, sharp (in tiie adult rellected ? ), body and inner lip slightly 

 erased, white ; pillar short, twisted, its anterior edge thickened and flaring 

 anteriorly, obliquely attenuated ; axis pervious ; canal almost obsolete, with no 

 siphonal fasciolc; operculum thin, brownish, pinna-shaped, the area of attachment 



