PLATE LI. 



Hemiastee, lacunosxjs Slocum (p. 97). 

 Field Mus. P 10342, type. 



Figure la. Upper surface of the test. 

 lb. Lower surface of the test. 

 lc. Lateral surface of the test. 

 Id. Posterior surface of the test, 

 le. Apical system, X 10. 

 If. Portion of anterior ambulacrum, X 8. 

 lg. Same, petaloidal region, X 8. 

 lh. Lateral view of tubercle, X 20. 

 li. Tubercle from above, X 20. 

 280 



