104 IOWA STUDIES IN NATURAL HISTORY 



down to 50 or even 100 fins., but the species of the continental 

 group do not seem to ever come up into the very shallow water. 

 The following list shows the echini of the present collection 

 which belong to the strictly littoral group: 



Eucidaris tribidoides Echinometra lucunter 



Centrechinus antillarum Clypeaster rosaceus 



Lytechimis variegaUis Mellita sexiesperforata 



Tripneustes esculentus Echinoneus cyclostonms 



Brissus hrissus 



In a recent study of the littoral echinoderms of the "West 

 Indies (1919, Publ. 281, Carnegie Inst., pp. 51-74), I have re- 

 corded 7 of these 9 species from Barbados and 6 from Antigua, 

 relying mainly on the field notes of Dr. W. K. Fisher who was a 

 member of the Iowa party. The present collection adds Lyte- 

 €hinus variegaUis to the fauna of Barbados and Clypeaster rosa- 

 ceus and Echinoneus cyclostomiis to the fauna of Antigua. 



Of the remaining nine species, eight unquestionably belong to 

 the continental groups. The ninth, the unique Pseudoholetia, 

 may possibly prove to be littoral but the depth at which it was 

 found is not recorded. The nine species are: 



Stylocidans affinis Lytechimis callipeplus 



Tretocidaris hartletti Lytechimis euerces 



Coelopleurus floridamis Genocidaris maculatus 



■Centrostephanus ruhicingulus Pseudoboletia occidentalis 



Agassizia excentrica 



Excepting only the two new forms, all these species were taken 

 by the ''Blake" near Barbados, and also near Dominica, Mont- 

 serrat or St. Cruz. Hence their occurrence in the present collec- 

 tion was quite to have been expected. There are no specimens 

 however of any of them from Antigua, all having been taken off 

 the southwest coast of Barbados in 25-100 fms. But practically 

 no dredging was done at Antigua except in the shallow harbors 

 and bays, owing to the high seas outside those sheltered areas. 



LIST OF SPECIES 



EUCIDARIS TRIBULOIDES 



Cidarites tribidoides Lamarck, 1816. Anim, s. Vert., 3, p. 56. 



