CARBONIFEROUS FOSSILS OF IRELAND. 47 



founded with is the Patella sinuosa of Phillips, from which it is readily distinguished by its nearly euntral 

 apex. Length one inch live lines, width one inch two lines, height two lines. 



Dentalium. Linn. 

 Gen. Ch. — Shell conical, tubular, slender, arched; open at both ends. 



Dentalium inornatum. M'-Coy. (PI. V. fig. 30). 



Sp. Ch. — Tube slightly arched, very gradually tapering, mouth circular; surface plain, smooth. 



This is the first example I have seen of the genus Dentalium in the Irish palajozoic rocks ; it is not unlike 

 the recent D. entalis, and like it, is smooth, and entirely without the longitudinal ridges which ornament so 

 many of the species ; but it is considerably smaller, seldom attaining, I should think, a greater length than one 

 inch ; the imperfect specimens usually found are little more than half that, and have a diameter of about three- 

 foiu-ths of a line. 



DITHYRA. 



Teredo (?) antiqua. M'Coy. (PL VIII. fig. 1). 



Sp. Ch. — Tube irregular, flexuous, nearly cyhndrical, about three-fourths of a hne in diameter ; irregu- 

 larly wrinkled transversely ; anterior end flattened, and terminating in two short tubuli. 



This curious shelly tube occurs occasionally in considerable abundance ; the specimens are usually about 

 three-fourths of an inch in length, and from one-half to three-fourths of a line in diameter, twisted in every 

 direction. The tube terminates distinctly in two smaller tubuli, whence I have placed it as a Teredo, although 

 with some doubt. 



Genus Solenopsis. M'Coy. 



Gen. Ch. — Transversely elongate, equivalve, inequilateral, beaks prominent, close to the anterior end; 

 anterior end short, rounded, closed ; posterior end elongate, truncated, slightly gaping. 



I have instituted the present genus for the reception of a few fossils of the carboniferous series, hitherto 

 ranked by Goldfuss and others with the genus Solen ; from this genus they are distinguished by their prominent 

 beaks, which are never terminal, and their rounded and closed anterior end. From Solenocurtus they differ in 

 being inequilateral ; from Nucula and Solenella they differ in the want of lateral teeth, and in their gaping, 

 posterior end. The few species I know are all from the Palaeozoic rocks, and scarcely differ except in size. 



Solenopsis minor. M'Coy. (PI. VIII. % 2). 



Solen pelagicus. Forth. (Not of Gold.) 



Sp Ch. — Width three times the length ; anterior end short, rounded; surface with irregular, concentric 

 strise. 



This species differs from the Solen pelagicus. Gold., in its being less elongate transversely, having a 

 broader anterior end, and being entirely without the sinus, which extends from the beak to the ventral margin 

 in that species ; from the Solen vetustus of the same author, which it more nearly resembles, it differs in not 

 being radiated, and in its strong, diagonal, posterior ridge. Length four lines, width eleven lines. 



Sanguinolites. M'-Coy. 



Gen. Ch. — Transversely oblong, convex, equivalve, very inequilateral ; dorsal and ventral margins paral- 

 lel, or nearly so ; anterior side short, rounded ; posterior side lengthened, obliquely truncated, gaping ; an 

 oblique ridge usually extends from the beak to the anal angle, but no flexure ; ligament external. 



