ON TWO NEW SPECIES OF ASTHI3NOSOMA. 



11 



Explanation of Plate II. 



Astbenosoma longispinum, Yosh. 



Fig. 1. Portion of abactinal side. Xat. size. 



2. Portion of actinal side. Nat. size. 



3. Arrangement of tubercles on abactinal side. Semi-diagrainuiatie. in. 

 interauibulacral row ; am. ambulacral row. 



4. Arrangement of tubercles on actinal side. Semi-diagrammatic. Letter- 

 ing as in foregoing figure. 



5. Portion of periproct and of adjoining coronal plates. Magnified, an. 

 anal plate ; per. periproctal plate ; bas. basal plate ; g. o. genital opening ; 

 mad. madreporic plate; rad. radial plate; in. interambulacrum ; am. 

 ambulacrum. Portions of plates not covered with membrane are shaded. 



0. Adjoining ambulacral (am.) and interambulacral (in.) plates near ambitus. 

 Magnified. 



7. End of hoof-capped spine. Magnified. 



Astheuosorua Ijimai, Yosh. 



Fig. 8. Portion of profile view. Xat. size. 



9. Portion of abactinal side of test, showing two rows of ambulacral (am.) 

 and interambulacral (in.) plates. X2. 



10. Portion of actinal side of test, showing two rows of ambulacral (am.) and 

 interambulacral (in.) plates. X2. 



11. Portion of periproct and of adjoining coronal plates. Magnified. Let- 

 tering as in fig. 5. 



12. Terminal portion of primary spines, showing the terminal segment and a 

 small portion of the crenulated shaft. Magnified. 



Printed April 30, 1897. 



