CONTRIBUTIONS TO PALAEONTOLOGY. 83 



GENUS DALMANIA (Emmrich). 

 DALMANIA ANCIIIOPS ( Green, sp.). 



Calymene : Cited with doubt by Brongniart as C. macrophihalma (Crus. fos. p. 16). 



Calyme:ie anchiops : Green, Monogiapb, p. 35. 



jlsaphiis laticostatus : Greex. Ibid. p. 49. 



Phacops qnchiops : Hall, in Foster & "\V liitney's Report of Lake Superior, p. 124*. 



Tills species, in the condition of fragments and casts, is not unfrequent 

 in the Schoharie grit of New-York. The original specimen is a partial cast 

 of the interior of the crust : the crust is removed from the greater part of 

 the head and mainly from the axis, presenting but a narrow border on the 

 lower margin, ani no portion of the surface is entire. The axis is a little 

 more than half as wide as the lateral lobes : in the caudal portion, it has 

 about thirteen rings ; and the lateral lobes have nine ribs, the last one 

 parallel to the axis. The frontal lobe of the glabella is wide across the 

 middle, somewhat narrowed and almost pointed anteriorly, and abruptly 

 contracted in front of the eyes. 



In the specimens, which are all casts, the anterior and middle lobes appear 

 as a single prominence, and the posterior lobe is very obscure. Sharp inden- 

 tations mark the longitudinal furrow. The border of the head is prolonged 

 posteriorly into spines ; and, although not positively determinable in the 

 specimens before me, it seems probable that the anterior border has been 

 produced, either as an acute extension, or as a distinct process in front, 

 while the centre of the occipital ring is produced into a short spine. These 

 characters, however, are not visible in the original specimen. 



In a small entire caudal shield there is a posterior spine of full one quar- 

 ter of an inch : the rings of the axis, and the lateral ribs in this one are 

 tuberculated. The caudal shield of the original fossil measures about one 

 inch and three-fourths across the anterior margin, with a length of about one 

 inch. In an impression in the stone, and still retaining part of the crust, and 

 a little larger than the original specimen, the length of the caudal spine is 

 five-eighths of an inch. Casts of the caudal shield, measuring from two and 

 a half to three inches, are not uncommon in the Schoharie grit ; and it is 

 one of these, which is the typical specimen of Green's Asayhus laticostatvs. 



The plaster cast of A. laticostatvs^ referred to in Green's Monograph, 

 measures a little more than three inches in diameter, and is nearly two 

 inches and a quarter in length. 



Geological formation and locality. In the Schoharie grit at Schoharie, 

 and in the Helderberg mountains. 



* At the time of writing for that Report, I had not seen the generic description of 

 Dalmania : these forms have been previously united under Phacops. 



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