L26 PALEONTOLOGY OF NEW YORK. 



The Ptgidiom is like that of P. Roivi, the axis bearing the same number of annu- 

 lations, nine or ten, but scarcely so wide or so strongly arched as in that 

 species ; the pleura are more flattened, the ribs, of which four or five may 

 be counted, being very faint, becoming obsolescent. The border is distinctly 

 thickened. 



Dimensions. The cast of the lower surface of the entire individual meas- 

 ures as follows : 



Body Cephalon. Thorax. Pygidium. 



Length — 35 mm. 12.5 mm. 13.5 mm. 9 mm. 



Width. 24 mm. 24 mm. 21mm. 19 mm. 



Observations. Of all the American Proiti which follow the type of structure 

 exemplified in P. Rowi, Green, this species is much the broadest and stoutest, 

 although it is closely allied in many details to several members of the group. 

 It may be important to note that this broad form has been found only in 

 the easternmost outcrops of the Devonian formations; while the narrowest 

 and most slender member of the group is from the far west (Eureka District, 

 Nevada). 



Distribution. In the upper limestones and sandstones of Indian Cove, Gaspe, 

 Province of Quebec. 



Proetus Prouti. 



PLATE XXIII, FIGS. 16-18. 



Pi tins Prouti, Shumard. Trans. Sf. Louis Acad, of Sci., vol. ii. No. 1, p. 110. 1863. 

 Proetus Davenportensis, Barbis. Proo. Davenport Acad. Nat. Sci., vol. ii, p. 287; pi. xi, fig. 8, and pi. xi 



revised, fig. 8. 1878. 



General Form and Proportions. Body elliptical or sub-ovate in outline; 

 length to width as 3 to 2. 



Surface convex, scarcely elevated, and conspicuously trilobate. 



Cephalon sub-semicircular, faintly produced at the anterior extremity. Bor- 

 der broad and prominent, deeply grooved in front and recurved at the edge, 

 becoming Hatter at the sides, the sulcus more shallow and narrower and 

 accompanied by a less conspicuous sulcus nearer the cheek. At the genal 



