80 BULLETIN OF THE 



Section DOLICHOTOMA Bellaedi. 



Type, Pleurotoma cataphracta Brocchi. 



The folds with which this species is credited are merely the projecting 

 margin of the pillar, and an obscure thickening, hardly to be compared to a 

 true plait. 



Genota viabrunnea n. s. 



Plate XIII. Fig. K. 



Shell solid, fusiform; with a smooth, brown, two-and-a-half-whorled vitre- 

 ous nucleus, the last whorl of which has semilunar riblets ; and eight slightly 

 turrited whorls; spire short, conical, rather pointed; the early whorls deli- 

 cately sculptured, the last two rather rude ; the aperture longer than half the 

 shell. Transverse sculpture in the earlier whorls (which are pure white) con- 

 sisting of rather crowded flutings depending transversely forward from the 

 sutural margin for a third of the width of the (visible) whorl, which then swells 

 outward, marked by strong growth lines, to a series of peripheral angular 

 nodulations which mark the course of the anal fasciole; on the fourth, fifth, 

 and sixth whorls, counting from the nucleus, the flutings are more regular and 

 elegant than in the earlier or subsequent turns, on the fifth and sixth they as 

 well as the growth lines are elegantly granulose or marked with small round 

 nodes, the resultant of transverse and spiral sculpture; the peripheral nodula- 

 tions also become more transverse and divided into three smaller nodules each, 

 from the same cause; on the seventh and eighth whorls the lines of growth be- 

 come more rude, the flutings and nodulation gradually vanish, and the sculpture 

 is reduced to obscure spiral ridges, finer and more uniform on and behind the 

 fasciole, and coarser, with a certain alternation of larger and smaller in size, be- 

 fore the fasciole ; the last three and a half whorls take on a warm brownish tint, 

 the fasciole being a still darker and somewhat livid madder brown ; the later 

 spiral ridges are also often somewhat darker than their interspaces. Aperture 

 narrow, canal short, broad, slightly recurved ; outer lip pnMuced in advance 

 of the sinus, thin, simple, sharp; body polished, slightly excavated; column 

 slightly twisted, swollen, white, smooth, attenuated in front, with no callus, as 

 long as the canal ; suture distinct, appressed, posterior surface of the whorls 

 behind the fasciole somewhat concave. Lon. of shell, 38.00; of aperture, 22.00; 

 max. lat. of shell, 16.5; of aperture, 6.5 mm. 



Habitat. Off Martinique, at Station 211, in 357 fms., fine yellow sand, liv- 

 ing; and near Barbados, at Station 295, in 180 fms., hard bottom; bottom 

 temperature 50°.7 F. Also south of Cuba, in 254 fms., coral, at U. S. Fish 

 Commission Station 2134. 



This fine shell is of unusual solidity and warm coloration for a deep-water 



species. None of the specimens showed any indications of thickening or 



striation of the aperture. Like many others, in the present unsettled state of 



the classification of the Pleurotomidce, its final place is somewhat uncertain, but 



January 26, 1889. 



