i§79-] y>^g Paleontologist. ^_ 23 



Size of the specimen from which this description is made about %. of an inch in diam- 

 eter in either direction. Attached to a fragment of limestone. 



This species differs widely from any that I know of, except a slight resemblance to C. 

 alternata. The type specimen is in the cabinet of Dr. L. B. Welch, the discoverer. 



Position and locality — Lower Silurian, Cincinnati Group, Clinton Co., O. 



Carnia alternata. (sp. nov.) (James.) 



{alternata — in allusion to the larger and smaller striae.) 



Shell angular, sub-hexagonal or sub-circular in outline. Dorsal valve moderately and 

 evenly convex. Apex at the cardinal margin. Surface marked by coarse rounded striae, 

 arranged in an alternating manner, about every other one being larger and more promi- 

 nent than the one intervening. All of the larger striae extend directly across the shell 

 and part of the smaller, but in some cases the latter come in by implantation about the mid- 

 dle. The striae are closely drawn together at the cardinal border in a puckered manner 

 and slightly bent to one side, the ends showing distinctly. Ventral valve and interior 

 not observed. 



This species resembles the preceding only in the drawing in of the striae at the cardinal 

 border; in all other features it is very different. 



The example used for this description is attached to a fragment of limestone and 

 measures in size 4x5 lines 



Found in the upper part of the Cincinnati Group, Clinton Co., O. 



GENUS MODIOLOPSIS, (Hall.) 

 Modiolopsis cuneiformis- (sp. nov.) (James.) 



[citneiformis — tapering in the form of a wedge.) 



Shell small, thin, subelliptical in outline, narrowing from about the middle to the pos- 

 terior end ; umbones low ; beaks slightly projecting and quite close together ; hinge line 

 slightly curved upward and about half the length of the shell ; posterior umbonal ridge 

 well defined ; posterior dorsal slope regularly rounded to the basal margin. Anterior end 

 forward of the umbones short and evenly rounded to the basal margin, which curves 

 gently to the posterior end. Widest part of the shell a little back of the umbones. 



This description is made from very symmetrical and perfect casts. Outer shell markings 

 unknown. The larger of two specimens is \% inch long from the anterior end to the 

 posterior end, and ^ an inch wide from the hing line to the basal margin, measuring just 

 back of the umbones. Greatest thickness through )^ of an inch ; the other specimen is 

 about half these dimensions. The posterior end may have been more pointed than 

 appears in the casts. 



This species differs from M. Cincinnaticnsis, Hall and ^^'hitheld, in the less proportional 

 width of the posterior portion, the evenly rounded posterior end, the evenly curved basal 

 margin, less prominent beaks and umbones, and less thickness of the shell generally. 

 And nearly the same differences may be stated in comparing with M. anodontoides , Conrad. 



Position and locality — Lower Silurian, Cincinnati Group. Found by Mr Lewis C. 

 Chamberlin (the possessor of the specimens now), near Lebanon, Warren Co , Ohio 



Modiolopsis SUbspatulata. (sp. nov.) (James.) [spatiilata — blade-shaped.) 



Shell subovate in outline; length more than twice the breath, which is nearly or quite 

 equal from just in front of the beaks to near the posterior end — the broadest part being 

 near the middle, measuring from the hinge line to the basal border. The anterior margin 

 rounds abruptly from the extremity of the hinge line to the basal border which makes 

 a slight and regular curve to near the posterior end where it rounds off to the cardinal line 

 slightly narrower than the other end. Valves depressed convex and flattened towards the 

 posterior end. Umbones low ; umbonal ridge inconspicuous with a slight depression 

 passing obliquely to the posterior basal margin. Cardinal line nearly straight and extend- 

 ing 2^ or more of the entire length of the shell. Surface slightly and regularly rounding 

 from the hinge line to the basal border, and marked by rather broad, indistinct, concentric 

 lines of growth. Beaks small, slightly angular, projecting conspicuously above the hinge 

 line, incurved, nearly in contact, and situated near the anterior end. 



Two examples used for this description are 2 inches in length and nearly an inch in 

 breadth, and about ^ of an inch thick measuring through the umbones. Two others, 

 seemingly the same species, are larger and more robust, with stronger lines of growth, 

 the umbonal ridge more conspicuous and much thicker through the body of the shell, the 

 valves being more convex. 



Locality — Clinton Co. O., and other places in the Cincinnati Group. 



BIBLIOGRAPHY. 



A "broadside " sheet which has been in the possession of the writer a long time — 20 

 years or more — laid by with other papers and overlooked until recently, seems to be of 

 sufficient interest to Paleontologists, at least to collectors of this region to justify this notice. 



