198 C. D. Walcott — Fauna of the Upper Taconic. 



Ptychoparia ? [Subgenus?) clavata, n. sp. 

 Plate 1, fig. 3. 



This is a minute trilobite, whose true relations are unknown. 

 With the exception of its clavate glabella, it is related to Soleno- 

 pleura ? Nana and 8. ? tumida by the course of the facial 

 sutures, wide fixed cheeks and small eye lobes. 



Formation and localities. — Cambrian. Limestones interbedded 

 in the shaly Taconic slates, \\ miles south of North Granville; 

 on the roadside a little north of school house No. 4, in the north- 

 east part of Whitehall ; on the roadside just west of the Low 

 Hampton crossing of the Poultney Eiver; and near Eock Hill 

 school house (No. 8), about a mile east of North Greenwich, 

 Washington County, N. Y. 



DESCRIPTION OF PLATE I. 



[The natural size of the specimens is indicated by the lines beside the figures.] 



Page. 

 Figure 1. — Solenopleura ? Nana Ford 196 



I, smooth variety of head; la, side outline of 1 ; lb, side view of a granu- 

 lose head that has faint glabella furrows; 1c, Id, pygidium associated 

 with the heads of this species. 



Figure 2. — Solenopleura? tumida, n. sp. __ 196 



2 and 2a, top and side views of head, except free cheeks. 



Figure 3. — Ptychoparia (?) clavata, n. sp 198 



Figure 4. — Microdiscus connexus, n. sp 194 



4, 4a, summit and side views of head ; 4Z>, associated pygidium. 



Figure 5. — Olenoides Fordi, n. sp 195 



5, head, except free cheeks ; 5a, associated pygidium ; 5b, associated free 

 cheek. 



Figure 6. — Ptychoparia (?) Fitchi, n. sp - 191 



6, head, except free cheeks. 



Figure 1. — Conocoryphe trilineata Emmons (sp.) 197 



7, finely preserved head with the exception of the narrow free cheeks ; la, 

 figure of specimen described by Dr. Emmons in his American Geology, 

 pi. i, fig. 16; lb, pygidium associated with heads and fragments of the 

 thorax. 



Figure 8. — Aristozoe Troyensis Ford 193 



8, cast of left valve. 



Figure 9. — Aristozoe rotundata, n. sp 193 



9, cast of the right valve. A row of vascular markings are quite distinctly 

 shown on the lower portion of the valve. 



Figure 10. — Byolithellus micans var. rugosa, n. var 191 



10, enlargement of a fragment to show the rugose surface. 



Figure 11. — Stenotheca rugosa Hall (sp.) 



II, 11a, side views of two specimens to show the variation in the concen- 

 tric undulations of growth ; 1 lb, enlargement of the surface of 1] . (For 

 description of this species see Bull. 30, U. S. G-eol. Survey, p. 128.) 



