THE FAUNA OF THE ST. JOHN GEOUP. 43 



sp.) of the Upper Cambrian (U.S. Geol. Smv., 6th Annual Report, 18t2, p. -il9), as figured 

 by Mr. C. D. Waloott, in his " Pahpontolog-y of the Eureka District," biit it is more tran,sverse, 

 is shorter in the hinge line, and is a much larger species. From K. cinguhila, the type of the 

 genus, it is readily distinguished by its surface markings as well as from var. pusilla 

 (Linuarss.) which occurs in Sweden a little above the horizon of our species ; the Scandin- 

 avian shell is much smaller, and is distinct by the ornamentation of its surface. 



Length, 7 mm. Width, 11 mm. Length of hinge line, 8 mm. 



Horizon and Localilij. In the slaty shales of Div. l.f, at Portland, N. B. 



N.B. — The apparent flatness of the umbones in this species may in part be due to the 

 conditions under which it is preserved. It has as yet been found only in the slaty beds at 

 Portland, where pressure may have distorted it in this respect. 



KXJTORGINA (?) PTERINEOIDES, n. sp. (Plate V. Fig. 19.) 



There is a small bivalve shell in the fine shales of Div l.c, which, if not a lamilli- 

 branch or phyllopod, would appear to be another species of this genus ; but if so, the valve 

 representing it, is somewhat distorted by pressure. It has the form of a wide Pecten or 

 Pterinea, with an apparent ear on one side of the umbo, and lunule on the other. The 

 umbo is central on the hinge line and slightly furrowed along the middle : the hinge area 

 is long and rather wide, and is marked by two faint furrows that diverge from the point of 

 the umbo to the outer margin of the hinge area ; this part of the margin is revolute, and 

 marked by two shallow pits opposite the umbo ; a sharp furrow along the posterial side 

 of the valve indents the hinge area. 



The surface of this shell is nearly smooth, but two or three radiating striœ are faintly 

 visible near the axial line, and there are numerous, but obscure, concentric strife which are 

 most clearly defined on the middle of the valve. 



Length, 3 mm. Width, 5 mm. 



Horizon and Localitj/. In the fine, dark-grey shales of Div. \.r, at Hanford Brook, St. 

 Martin's. 



ORTHIS, Dalman. 



Orthis BillinCtSI, Hartt. 



Orthis BiUingsi, Hartt, Acad. Geol. 2ud Ed., p. 644, Fig. 223. 



Orthis BiUingsi, Hartt, U. S. Geol. Surv., Bull. 10, p. 11, Plate I. Fig. 1, Ib-d. 



This common species has been so fully described by Messrs. Hartt and "Walcott, that it 

 seems unnecessary at present to enter into any further description of it, except in so far as 

 it may be necessary to contrast it with a small species hereafter described, that is accociated 

 with it. It may be said, however, in this connection that the species O. BiUingsi, shows 

 considerable variation in form during its growth ; at first it is as long as wide, and has a 

 deep median sinus ; at a later stage it is nearly twice as wide as it is long, and in the adult 

 staffe becomes once and a half as wide as it is long. 



*&• 



Orthis Quacoensis, n. sp. (Plate V. Figs. 20, 20a, b and c.) 

 A small species. Subquadrate to semi-elliptical in outline, broader than long, widest 



