PLATE VII. 



Page 

 Scaphiocrinus elegans W. and Sp. (MS.) 138 



Fig. la. Anterior side of the specimen, showing the ventral sac and the anal open- 

 ing low down in the sac. (Only the lower half of the specimen is drawn.) 

 lb. ' Posterior side of the specimen. (Kaskaskia group, Kentucky.) 



Scytalocrinus validus W. and Sp. (MS.) 138 



2a. Lateral aspect of a specimen with arms ; the anal opening located anteriorly 



in the lower part of the ventral sac. 

 2b. The ventral sac somewhat enlarged. 



3. Anterior side of the sac of another specimen. (Both from the Keokuk group, 



Indiana. 



Decadoceinus geandis W. and Sp 138 



4. Anal opening occupying the anterior side of the sac a little above midway ; 



the pores at the lower part of the sac passing through the test, as shown 

 upon the lateral edges of the plates. 



5. A specimen showing the posterior side of the sac. (Keokuk group, Craw- 



fordsville, Ind.) 



Scaphioceinus unicus Hall 138 



6. Posterior side of a specimen, showing the ventral sac to its full length. 



(Locality and position same as last.) 



Scytaloceinus (sp. undet.) 138 



7. Anterior view of ventral sac, showing the pores along the sides of the plates, 



and the position of the anus. (Kaskaskia group, Kentucky.) 



Scaphioceinus Swallovi Meek and Worthen . 138 



8. Portion of the ventral sac ; composed of stellate plates with pores around 



their edges. The ducts of the pores plainly visible in places where the 

 plates are slightly pushed out of position 



Auloceinus Agassizi W. and Sp. (MS. Nov. gen. and n. sp.) . . 138 

 (cnjAds a small tube, Kpivov a lily.) 



9. Right postero-lateral aspect. Anus at the end of a special tube, given off 



half way down from the anterior side of the ventral sac. Sac and tube 

 profusely perforated by pores. (Keokuk group, Indiana.) 



Cosliocrinus venteicosus (Hall) 138 



10f(. Posterior side of the ventral sac. 

 10b. Anterior side of it. 



Cyathoceinus nodosus W. and Sp. (MS.) 137 



11a. The anus at the end of the ventral sac slightly excentric in position, and 

 closed by eight or nine plates forming a pyramid. 

 lib. Distal end of the ventral sac enlarged. 



Cyathocrinus beevisacculus W. and Sp. (MS.) 137 



12a and b. The ventral sac with the anus in the same condition as in the pre- 

 ceding species. 



(All specimens are in the collection of Wachsmuth and Springer.) 



