PLATE X. 



Page 

 Aech2eoceinus lacunosus (Billings) , . . . 255 



Fig. 1. Posterior view of the type specimen. (Museum Geol. Surv., Canada.) 



Abch^ocrinus miceobasalis (Billings) 256 



2a. Specimen with arms and stem. (Coll. John Stewart.) 

 25. Another specimen. (Same collection.) 

 2c. Basal aspect. (Same collection.) 



Aech^oceinus pyeifoemis (Billings) 255 



3a. The type specimen. (Museum Geol. Surv., Canada.) 



3b. A crushed specimen, showing the arms. (Same collection.) 



Aech^oceinus dbsideeatus W. E. Billings ........ 257 



ia. The type specimen with arms; the left posterior radius in front. (Coll. 



W. K. Billings.) 

 45. Dorsal aspect of the calyx. (Coll. W. and Sp.) 



Diaboloceinus hieeoglyphicus W. and Sp 252 



5a. Dorsal aspect of a large specimen. (Coll. W. and Sp.) 

 5b. Side view of the same. 



5c. Anal side of a small specimen. (Same collection.) 

 (Figs. 2c and 5a are drawn with anal side up.) 



