PLATE L. 



Page 

 Periechoceinus necis (Winch, and Marcy) 524 



Fig. la. Posterior side of an internal cast. (Coll. W. C. Egan.) 

 lb. Ventral aspect of another cast. (Same collection.) 



Pbeiechoceinus infelix W. and M 525 



2a. An interior cast in a side view. (Same collection.) 



2b. Ventral aspect of an internal cast. (Same collection.) 



2c. Lateral view of a specimen figured by S. A. Miller as Saccocririus Egani. 

 (Same collection.) 



2d. Ventral aspect of another cast, figured as S. Egani. (Same collection.) 



Pbeiechoceinus oenatus Hall and Whitf 527 



3a. Gutta-percha cast from a mould in the rock, showing surface markings; 



posterior side. (After Hall and Whitfield.) 

 36. Anterior view of an internal cast. (After Hall and Whitfield.) 



Peeiechooeinus tennesseensis (Hall) 528 



4. Posterior view of Eoemer's type specimen. (After Roemer.) 



Peeiechockinus uenifoemis (S. a. Miller) 526 



5a. Posterior view of an internal cast. (Coll. W. C. Egan.) 

 56. Ventral aspect of another cast. (Same collection.) 



Peeiechooeinus speciosus (Hall) 521 



6a. The type specimen. (After Hall.) 



&b. Part of an arm enlarged. (After Hall.) 



Peeiechooeinus maecouanus (Winch, and Marcy) 523 



7a. Side view of an internal cast; anal side to the left. (Coll. AV. C. Egan-) 

 lb. Anterior view of the dorsal cup. (Same collection.) 



