248 PALAEONTOLOGY OF NEW-YORK. 



crushed or absorbed. The portion of the cheek supporting the inner and upper margin of 

 the eye still remains, in the foem of a subconical tubercle. 

 Fig. 3 i. View of the same specimen, showing the caudal shield and front of the buckler. 



This specimen, and one or two others which I have obtained, are scarcely recognizable 

 as the same species, from the lobes of the glabella being obliterated, and the eye appearing 

 more like the preceding species in form, or altogether obliterated. The species is clearly 

 contractile, as well as those having fewer articulations in the caudal shield. 



Position and locality. This species occurs in the lower shaly layers at Middleville, asso- 

 ciated with Ceraurus. It is likewise found in the higher part of the rock at Watertown, 

 Jefferson county, but has not been observed in the succeeding shales. (State Collection.) 



305. 2. PHAC0PS1 LATICAUDUS. 



Pl. LXIV. Fig. 3. 



Pygidium broadly subtriangular, the middle lobe with about fourteen segments ; lateral 

 lobes each with ten or more undivided segments, which terminate in a thickened continuous 

 margin. 



It is impossible to decide satisfactorily in regard to this species, since the surface markings 

 are entirely obliterated in the specimen. The form of tliis part of the species is very similar 

 to that on PI. 60, fig. 1 ; but the axial lobe extends nearly to the posterior margin, and the 

 segments of the lateral lobes are less numerous and of a different character. An equal 

 difference will be perceived when compared with Jlsaphus tyrannus of Murchison, before 

 cited. 



Position and locality. In the upper subcrystalline portion of the Trenton limestone, at 

 Turin, Lewis county. On the authority of Dr. Budd. (Cabinet of Dr. Emmons.) 



306. 3. ASAPHUS1 NODOSTRIATUS. 



Pl. LXI. Figs. 1 a, b. 



Several fragments of the form here represented have been obtained, but nothing which 

 will enable us to decide satisfactorily as to the character of the entire animal. The fragment 

 appears to be the middle lobe of the buckler or glabella, and is in form very similar to the 

 glabella of Jlsaphus angustifrons ; but the surface markings are different. 



It is impossible to decide positively whether this fragment be a glabella, or the labrum 

 of some species, the form being similar to the labrum of Calymene. The surface markings 

 are sufficient to distinguish it from any other species known to me in the Trenton limestone. 



Fig. I a. The fragment, natural size. 



Fig. \ b. h magnified portion of the surface, showing the lamellosc stris, with small nodes which 

 interrupt the lines. 



Position and locality. All the specimens known, are from the lower part of the Trenton 

 limestone, near Watertown. (state Collection.) 



