PLATE LXVIII. 



Platycbinus vebbucosus White 705 



Fig. la. The type specimen. (Mus. Comp. Zool.) 



lb. Oblique view of the dorsal cup. (Coll. W. and Sp.) 

 1c. Another specimen ; dorsal aspect of the calyx. (Same collection.) 

 Id. Lateral aspect of a variety from New Mexico, showing the anal opening. 

 (Same collection.) 



Platycbinus pocillieoemis Hall 706 



2a. Lateral aspect of the dorsal cup (the ornamentation from another specimen). 



(Coll. W. and Sp.) 

 25. Base of a specimen with larger nodes. (Coll. W. and Sp.) 



Platycbinus Yandelli 0. and Sh . 706 



3a. Dorsal aspect of the calyx; a very mature specimen. (Same collection.) 

 35. Ventral aspect of the same specimen. 

 3c. Posterior view of same. 



Platycbinus Yandelli, var. peeaspee 708 



4a. Lateral view of a specimen with arms. (Mus. Comp. Zool.) 

 45. Dorsal aspect of the same specimen (the stem removed). 



Platycbinus sculptus Hall 691 



5. Specimen from New Mexico, lateral view of the calyx. (Coll. W. and Sp.) 



Platycbinus paevinodus Hall 696 



6a. Side view of the type, the specimen somewhat flattened. (Mus. Comp. 



Zool.) 

 6b. Anterior view of another specimen less distorted. (Coll. W. and Sp.) 



Platycbinus peculiaeis W. and Sp. . . 700 



7a. Posterior view of the calyx ; the nodes partly eroded by weathering. (Coll. 



W. and Sp.) 

 lb. Ventral aspect of the same specimen. 



Platycbinus geometeicus W. and Sp 697 



8. Another type specimen. (Coll. W. and Sp.) 



