154 PALAEONTOLOGY OF NEW-YORK. 



PBODUCTELL.E OF THE CORNIFEROUS LIMESTONE AND HAMILTON 



GROUP. 



Productella subaculcata. 



PLATE XXIIL 



Pnductut subaevleatm : Murchisoh, 1840, Bull, do la Soc. Geol. de France,Vol. xi, pa. 256, pi. 2, f. 9 a,b,e. 



Ltpttmafragaria : J. de C. Sowebbz, 1840, Transac. of the Geol. Society of London, 2d series, Vol. ▼, 



pa. 704, pi. 56, J^ 5 and 6. 

 —— oblongaf : Idem, Ibid, pi. 53, f. 29; not Pandeb. , 



Producta : Phu.lips, 1841, Pal. Foss. of Cornwall, pa. 59, pi. 25, f. 100. 



Producttu tpinulostu (partim) : Db Konihck, 1843, Desc. des Anim. foss. du terr. carb. de Belginm, 



p. 183 (flg. cxclnsis) ; not Sowebbt. 



— nibacuUaltu (partim) : De YBBNEiriL, 1843, Russia and the Ural Mountains, Vol. ii, pa. 282, pi. 16, 



f. 9, a, 6,0. 



(partim) : De Ketseblino, 1846, Relse in das Petschora-land, pa. 203, pi. 199 (fig. ex.). 



Strophalotia subacuhata ; KiBO, 1846, Ann. and Mag. of Nat. History, Vol. xviii, p. 28. 



Producttu tubaculeatut : De Kohinck, 1846, Mem. de la Soc. royale d6s Sci. de Liege, Vol. iv, pa. 249, 



pi. 16, f.4o-d. 



" " De Kobihck, Recherces sur les Anim. fossilea, 1847, pa. 142, pi. 16, f. 4Ja, 6, e, d. 



Ventral valve gibbous; length and breadth about as seven to eight : 

 hinge-extremities angulated, and the margins being contracted a little 

 below form small ears, while below this contraction the sides are 

 regularly curved and the front is broadly rounded. The umbo is con- 

 siderably elevated above the hinge-line, and the apex incurved. 

 Surface marked by closely arranged concentric striae, and studded with 

 slender rounded spines. On the upper part of the shell, and on the 

 ears, these spines are round at the base, and rise directly from the sur- 

 face. On the middle and lower part of the valve, there is a slight ele- 

 vation of the surface a little above the base of the spine, but not a de- 

 fined ridge. The number of spines on the individual figured has been 

 sixty or more. 



The following is the description of this species, given by De Koninck : 



" Shell small, semiglobose, rounded. Dorsal valve not sinuate, very 



" gibbous, rather regularly arched. The surface is ornamented with a 



" great number of very faint striae of growth, and scattered over with 



" tubes of which there usually remains only the circular or slightly elon- 



