48 PALEONTOLOGY. 



0. prosperum and 0. discors of Barrande, though it tapers more gradually 

 than either of these. 



The specific name is given in honor of Clarence King, esq., the geolo- 

 gist in charge of the United States Geological Survey, by which the fossils 

 here described were discovered. 



Orthooeras (undt. sp.). 



Plate 2, fig. 9. 



This is a mere fragment, consisting of a cast of most of the non- 

 septate part of the shell. It shows scarcely any taper from the anterior to 

 the posterior end, and presents a slightly oval section ; while its rounded 

 posterior end shows that the septa were rather deeply concave, and the 

 siphuncle nearly or quite central. If new, it may be called 0. parallelum. 



Locality and position. — Babylon HilL White Pine Mining District, 

 Nevada; Devonian. 



ARTICULATA. 



GEUSTACEA. 



PHAOOPSIDJE. 



Genus DALMANITES, Auct. 

 Dalmaijites (undt. sp.). 



Plate 1, figs. 11 and 11 a. 



Of this Trilobite, there are, in the collection, only a few imperfect 

 moulds and casts of the pygidium. These show this part to have been 

 subtrigonal in general form, with the posterior extremity rather acutely 

 pointed, and extended, in some cases, even farther back than indicated by 

 the dotted lines in fig. 11a. It seems to be rather depressed, with the 

 mesial lobe narrower than the lateral, and provided with about fifteen seg- 

 ments, with space enough at the posterior end for two or three more. The 

 lateral lobes have each about thirteen segments, which extend out nearly 

 at right angles from the mesial lobe anteriorly (excepting at their curved 

 outer ends), and become gradually more oblique posteriorly. They extend 

 nearly to the border, and only show the faintest traces of a mesial linear 



