502 GEOLOGICAL SURVEY OF THE TERRITORIES. 



convex, sometimes sliowiiig: a slight tendency to become shouldered 

 above, last one I'oruiing- about half the entire length of the shell, gen- 

 erally a little wider above, and narrowed and somewhat pioduced 

 below; suture well detined, in consequence of the convexity of the volu- 

 tions; nperture narrow, slightly longer than the spire, acute above, and 

 narrowing to a small, well-dctined sinus at the base of the truncated 

 coluuu'lla, which is provided with two small iblds, one of which is formed 

 by the twisted lower edge of the truncated columella, while the other 

 occupies a i)osition a little above, and passes around more obliciueiy ; 

 surface ornamented by comparativ^ely rather strong, regular, vertical 

 ridges or folds that sometimes become nearly or quite obsolete on the 

 body volution, es[>ecially below its upper part. Crossing these folds and 

 the depressions between them, much smaller revolving ridges and fur- 

 rows may be seen on well-preserved specimens, though these are also 

 sometimes obsolescent, excepting around the lower part of the body 

 volution. 



Length of a medium-sized adult specimen, 0.50 inch ; breadth, 0,25 

 inch ; angle of spire, about 42^. 



This species will be at once distinguished from the last by its propor- 

 tionally more prominent spire and less expanded body volution. It is a 

 much more abundant shell tlian the last, being found often iu considt?r- 

 able numbers clustered together. 



Locality and position same as last. 



Admete? subfusiformis, Meek. 



Shell subfusiform, with the length nearly three times the breadth; 

 spire elongated, conical, turreted ; volutions seven or eight, convex; 

 last turn more than half the entire length; suture well defined, in con- 

 se(pience of the convexity of the whorls; aperture narrow, equaling 

 about two-fifths the entire length of the shell, angular behind, and nar- 

 rowing below to a small, sharply-defined notch at the base of the trun- 

 cated columella, which seems to bear two suiall folds near its lower part, 

 one being formed by the twisted and truncated lower magin ; inner iip 

 a little thickened; surface ornamented by distinct, regular, vertical 

 folds that are nearly or quite obsolete on the body volution below its 

 upper part, and regular revolving lines quite well defined on the body 

 turn, especially its lower part, and appear to be obsolete on those of the 

 spire; lines of growth moderately distinct. 



Length, 0.50 inch ; brea<lth, 0.20 inch ; angle of spire, about 30°. 



This species differs even more strongly from the last than that form 

 does from the species rhomboiclcs, having a much more elevated spire and 

 a proportionally smaller body volution and a))erture. In ornamentation 

 the three forms, however, are much alike. The species here under con- 

 sideration shows a somewhat more thickened inner lip than I have yet 

 seen in either of the others. 



For the reasons already explained, this and the last may have to take 

 the names Turrieula grcgaria and T. .snbfi(fii/ormis,\l'i\\\ three do not, as 

 suggested further back, require to be grouped together as a new section, 

 under the names Admctopsls rhomhoides, A. gregaria^ and A. isuhfu.siformis. 



Locality and position same as last. 



TURRITELLA COALVILLENSIS, Meek. 



Shell attaining ? large size, elongate-conical ; volutions apparently 

 ten or more, distinctly convex, the most prominent part of those of the 



