122 CLARK. 



larly scattered and are comparatively few in number, averaging 

 from 12-15 per sq. cm., while the papillae are even less numerous, 

 averaging in the same individuals, 6-12 per sq. cm. The 

 largest specimen before me is 170 mm. long by 23 mm. in thick- 

 ness ; the smallest is 40 mm. by 14 mm. The color of the 

 alcoholic specimens is brown, indistinctly marked with spots and 

 blotches of black ; the pedicels are yellow especially at the tip; 

 the tentacles are yellow ; the body-wall is thin. In formalin 

 specimens the body-wall is thick, the ground color is much 

 lighter and the pedicels and tentacles are almost white. One of 

 the alcoholic specimens is lighter than the others and very 

 strongly tinged with yellow. Mr. Carpenter says in his field 

 notes on this species : " Color, a general brown in varying 

 shades. Several specimens have a darker color approaching 

 black. Can be picked up almost anywhere along the reef-pro- 

 tected shore after a little search among the broken rocks." The 

 twenty-one specimens which are in proper condition for a thor- 

 ough examination showed an interesting diversity in the number 

 of tentacles and Polian vesicles : 



2 had 21 tentacles. 



3 



had I 



Polian vesicle 



3 " 20 



8 



" 2 





3 " 19 



5 



" 3 





I " 18 



3 



" 4 





I " 15 



I 



" 5, 





I " I2(?) " 



I 



" 8 





The specimens with twelve and fifteen tentacles were very much 

 contracted and I could not be positive of the number but it was 

 certainly much smaller than normal. The stone canal was 

 always single and, except in two cases, free. It was sometimes 

 very small but in one specimen it was 4 mm. long and distinctly 

 pear-shaped. Cuvier's organs were present in a few individuals 

 but in most cases they had either been discharged or were never 

 present. After a careful study of Professor Heilprin's descrip- 

 tion ^ and figures, I am convinced that the form which he identi- 

 fied as H. floridana Pourt. is really this species, suriiiainensis. 

 The reasons for this conclusion are as follows : There is nothing 



