PLATE 103 B. 



Page 



Fig. 1 a - g. Leptoc(elia flabellites. 449 



1 a, b. Ventral and dorsal views of a specimen of this species. 



1 c, d. Dorsal and profile views of a specimen of the ordinary form of this species. 



1 e. Interior of a specimen with rounded extremities. 



1/. Interior of the dorsal valve of this species. 



1 g. The interior of the dorsal valve, showing the cardinal process, crura and crural plate, 



restored from cavities seen in a cast. 



Fig. 2 a - g. Leptoc<elia pimbriata. 450 



2 a, b. Dorsal and ventral views of a specimen of ordinary size. 



2 c. Front view of a specimen a little greater than the ordinary size, and which has the 

 fimbriated expansion extending below the cardinal angles. 



2 d. The ventral side of the preceding specimen, enlarged two diameters. 



2 d-\- St 2 d — . Dorsal and profile views enlarged the same as the preceding. 



2 e. The interior of the ventral valve, showing the cardinal teeth and the muscular impression. 



2 c (bis). The interior of the dorsal valve, showing the muscular impression, the cardinal 



process, the obitque lamella, median septum and bases of the crural processes. 

 2/. The same enlarged. 



2 g. The specimen fig. 2 e enlarged, to show more distinctly the teeth and muscular impressions. 



Fig. 3 a, b, c. Leptocoelia dichotoma. 452 



3 a. Dorsal view of the specimen. 

 3 b. Ventral view of the same. 



3 c. Front view, showing the outline, the de]>ression of the dorsal valve, and the incurved 



beak. 



Fig. 4 & 5. Leptaccelia planoconvexa. 



Atrypa planoconvexa : Pal. New- York, Vol. ii, pa. 75, pi. 23, f. 11. 



4 o, b. Dorsal and ventral views of a specimen of this species. 

 f>. Interior of the dorsal valve of this species. 



Fig. 6. Pholidops squamiformis. 490 



6 a. Interior of a siwcimcn of the natural size. 



6 b. The same enlarged. 



Fig. 7. Pholidops ovatus. 490 



7 a. Exterior of a specimen of the natural size. 



7 b. The same enlarged. 



Fig. % a - d. Pholidops terminalis. 490 



8 a. The exterior of the shell, of the natural size. 



8 b. Two valves in conjunction. It is not determined that these valves are in their natural 

 relations, and no articulating pi-ocesse» have been observed. 



8 c. The interior of an(.ther spcchnen. 



8 d. The same enlarged. 



