DERMATODIADEMA HORRIDUM. 



63 



Dermatodiadema horridum A. Ag. 



Dermatodiadema horridum A. Ag., Bull. M. C. Z. 1898, XXXII, No. 5, p. 70; Plate V, 



figs. 6, 7. 



Plates 24, figs. J,-12', 25; 26, figs. ^ 5, ^; 27; 28, figs. 1, 2-, 29, figs. 1-j,. 



D. liorridum is comparatively flat (PI. 24, fig. 8) with a large apical 

 system (PI. 24, fig. 9). The anal system is covered by a number of small 

 plates (PL 24, fig. 9). Those immediately surrounding the anal opening are 



20iimi. 



Fig. 95. D. horridum. 



D. HORRIDUM. 



elongate and somewhat larger than the others (Pis. 27 ; 28, figs. 5, 4), which 

 are irregularly arranged in concentric rows or dotted over the surface of the 

 anal system. The anal plates are covered with miliary spines. Those near 

 the anal opening are fully as large and long as any of the miliary spines of 

 the test. 



The greater number of the specimens collected were about 20 mm. in 

 diameter. When alive the test is claret-colored. The suckers and gills are 

 somewhat darker and stand out prominently among the lighter-colored 



