MUSEUM OF COMPARATIVE ZOOLOGY. 97 



Ringiciila nitida Verrill. 



Ringicula nitida Verrill, Am. Journ. ScL, V., 3d series, pp. 6, \Q, 1873. H. Moriet, 

 Journal de Conchyl., Vol. XXVI. p. 127, 1878. 



Ponrtales, bed of the Gulf Stream, 447 fms. Station 43, 339 fms. Yuca- 

 tan Strait, 640 fms. 



This is very different from Ringicula semistriata D'Orbigny (Sagra, Moll. 

 Cub., II. 103, Tab. XXI. figs. 17-19), and considerably larger. 



It has six whores ; the anterior fold on the column is distinctly the largest ; 

 the outer lip in mature specimens is thicker in the middle and anteriorly than 

 elsewhere ; the parietal tooth is obsolete ; and there is in perfect specimens a 

 well-defined area on the base, anterior to the junction of the outer lip and 

 body, which is distinctly grooved, the remainder being smooth. It reaches a 

 length of 7.5 and a breadth of 5.00 mm. 



Bulla abyssicola n. s. 



Shell of moderate size, and nearly the shape of B. ampulla, but proportion- 

 ately wider behind, white with an ill-defined band of pale yellow brown en- 

 circling the peri[)]iery ; aperture as long as the shell ; outer lip simple, nearly 

 straight, rounded before and behind, not extending beyond the summit of the 

 left side of the shell ; apex depressed, immersed, forming a slight pit with none 

 of the whorls visible ; surface ornamented with fine, minutely punctate spiral 

 grooves, more crowded before and behind, more distant about the periphery, 

 from four to twelve in the width of a millimeter and from eight to ten punc- 

 tations in the length of a millimeter, according to the part of the shell exam- 

 ined ; besides these there are numerous still finer stria3, also punctate, but 

 more finely, which, when very faint, appear like rows of very faint puncticu- 

 lations ; otherwise the surface is smooth, or even polished, the lines of growth 

 hardly perceptible ; aperture narrow behind, wide in front, the pillar reflected, 

 and a thin layer of callus evenly spread over the body within the aperture ; 

 proportions of younger specimens much the same, but a little more pointed 

 at the extremities. Lon. of shell and aperture, 12.75. Max. lat. of shell, 9.0 ; 

 of aperture, 5.25 ; min. lat. of aperture, 1.5 nmi. 



Yucatan Strait, 640 fms. Station 43, 339 fms. (young). 



The genera of these opisthobranchiates must always be uncertain in the 

 absence of the soft parts. To the species here described from the shells alone 

 the generic names applied must necessarily be provisional. The present one 

 shows no characters in the shell by which it might be separated from the typi- 

 cal species of the genus, unless it be the absence of distinct coloration which 

 we should naturally expect in a species from great depths. 



VOL. IX. — NO. 2. 7 



