CARBONIFEROUS FOSSILS OF IRELAND. Ill 



ill the Producta Edelburgensis. There are numerous small spines on the surface, but, wlien broken away, they 

 leave so small a mark, that they are frequently overlooked. Length one inch, width two and a quarter inches. 

 This is the usual size of specimens. 



Producta laxispina. Phil 



Producta laxispina. Phil. Geol. York, and Pal. Fos. 



Sp. Ch. — Hemispherical, hinge-line long, ears large ; surface smooth, with greatly lengthened, obsolete, 

 tubercles, irregularly placed. 



This shell has much the appearance of the Producta spinosa, but the length of the hinge-line, and the 

 great size of the ears, at once distinguish it ; its comparatively smooth surface distinguishes it from the other 

 allied species ; the spines are very remarkable, they are so much elongated as almost to assume the appearance 

 of ribs, they are not strongly marked. Length one inch, width one and a quarter inches. 



Producta lirata. Phil. 



Producta lirata. Phil. Geol. York. 

 Sp. Ch. — Small, subcylindrical, very gibbous; beak large; hinge-line equal to the width of the shell; ears 

 small, flattened, rectangular ; front semicircular ; surface smooth, marked towards the margin with few, irregu- 

 lar, longitudinal ridges. Length six Unes, width seven lines. 



Producta lob at a. Sow. 



Productus lobatus. Soio. Min. Con Producta lobata. Phil. Geol. York. 



Sp. Ch. — Subcylindrical, ears small, acute; dorsal valve divided into two lobes by a deep, mesial sul- 

 cus ; radiating ridges thick, rounded, smooth, finer, and reticulated by concentric wrinkles on the rostral portion ; 

 a few small spines, irregularly placed. 



This species closely resembles the Prod, concinna, differing chiefly in the greater coarseness of the longitu- 

 dinal strise, and its very deep, mesial depression. Length eight lines, width nine lines. 



Producta longispina. Sow. 



Productus longispinus and P. Flemingii. Sow. Min. Con. 



Sp. Ch. — Eared, dorsal valve gibbous, with a mesial depression ; obsoletely ribbed longitudinally, with se- 

 veral very long, cylindrical spines. 



This little species is chiefly remarkable for the great length of the spines ; it is very common in the Scotch 

 millstone grit, but is rare with us. It resembles the P. concinna, but is much smaller, neater, more finely stri- 

 ated, and has a smaller portion of the beak reticulated. Length about five lines, width the same. 



Producta margaritacea. Phil. 



Producta margaritacea. Phil. Geol. York. 



Sp. Ch. — Semicircular, depressed ; gibbous towards the beak ; radiating ribs coarse, rounded, smooth ; a few 

 large spines on the ears and sides of the shell. 



This species bears a considerable general resemblance to the P. ]iectinoides, but is wider, greatly more de- 

 pressed, and the radiating ribs are much smaller, more convex, and do not divide in the remarkable manner of 

 that species ; the present shell has also large lateral spines, of wliich the other has seldom any trace. Length 

 one inch, width one inch three lines. 



Producta Martini. Sow. 



Anomites productus. Martin, Pet. Derb. — Productus Martini. Sov~. Min. Con. 

 Sp. Ch. — Semicylindrical, very long, expanded at the margin ; front flat ; surface irregularly spinous, with 

 smooth, flexuous, frequently branched strioe ; ventral valve flat on the top; length nearly three times the width. 



