OVULACT.*:ON-KL.EINELLA. 179 



pressed incremental lines, and the faintest trace of spiral linear 

 markings ; a depressed line or sulcus indicates a previous resting 

 stage half a whorl behind the present thickened aperture in the 

 older specimens ; in the younger, the varical sulcus is three quarters 

 of a whorl behind the aperture. The apex in the older shell is per- 

 forate, the whole rounding over the perforation, and the spire in- 

 visible ; in the younger specimen the perforation is proportionally 

 wider, and about half a turn can be seen. The lines of growth be- 

 come stronger and more regularly grooved as they pass over the 

 summit into the pit. The aperture is very narrow, curved with the 

 profile of the shell, and extending beyond the summit. Unlike 

 Cyproea, the thickening of the outer lip is altogether internal, simple, 

 and, smooth, the callus opposite is narrow, with a sharply-defined 

 abrupt outer margin, and the inner margin raised sharply up paral- 

 lel with the outer lip, with which it is continuous at the extremi- 

 ties: the flat part of the callus is widest anteriorly, polished but not 

 smooth, but the raised edge is without teeth or transverse striation 

 of any sort. The extremities of the aperture are elevated to follow 

 the profile of the body of the shell. Lon. of largest specimen, 5'5 ; 

 max. lat. 3'0 mill. (Dall.}. 



Off Havana (Sigsbee) in 450 fms ; West of North Bernini, Bahamas, 

 in 200 fms., sand (Dr. Rush). 



0. meekii DALL, I. c., p. 43, pi. 33, f. 3, 4. 



This extremely interesting shell is well shown by the figure. 

 There can be little question as to its probable relations. The char- 

 acters of the aperture are essentially different from anything among 

 the Cyprceidce, and it has not the polished laquer which species of 

 that family owe to the expanded mantle-margin. Only one speci- 

 men was obtained at either locality (Dall). 



Genus KLEINELLA A. Adams, 1860. 



Kleinella AD., Ann. and Mag. Nat. Hist. (3), v, p. 302, April, 

 1860, type K. cancellaris. 



Shell ovate, thin, umbilicate, with cancellated surface ; spire pro- 

 duced, the apex obtuse; aperture elongated, anteriorly produced 

 and entire ; inner lip thin, simple ; outer lip angled behind, straight 

 in the middle, margin acute. 



This genus most nearly resembles Adceon, but is without any fold 

 on the columella; the umbilicus moreover is wide and deep, and the 

 surface of the shell is cancellated. The outer lip forms an angle 



