228 VERRILL 



but on the proximal part of the rays they gradually diverge and two 

 or three short rows of intermarginal ossicles are interpolated in the 

 interradial angles. 



The marginal plates in both rows are a little convex and lobate. 

 The outer surface is oblong-elliptical, or squarish with rounded 

 corners, united by apophyses. Their transverse diameter is often 

 but little greater than the longitudinal one, distally, but they become 

 more transversely elongated proximally. Their clusters of spines 

 do not much exceed those of the dorsal and lateral ossicles, and 

 therefore they are not so conspicuous as in H. leviuscula and some 

 other species. It often requires close examination to distinguish 

 them from the adjacent clusters, but in other cases they are larger 

 and more regular, and quite noticeable. 



The peractinal ossicles form a regular row of small, rounded 

 plates, one standing opposite each adambulacral and closely united 

 to it and to the opposite inferomarginal. This row often disappears 

 at about the middle of the ray, but may extend farther, sometimes 

 nearly to the tip. The plates bear divergent clusters of spinules, 

 usually smaller than those on the adjacent plates, but otherwise 

 similar. 



The adambulacral plates mostly bear two transverse divergent 

 series of small, unequal spines, usually standing in three or four or 

 more pairs on the external surface of the plate, and regularly 

 decreasing in size from the inner toward the external ones. The 

 inner or ambulacral end of the plate bears two, rarely three, unpaired 

 spines in a median row. The inner one, or furrow-spine, is attached 

 deep within the furrow and usually projects horizontally. It is very 

 slender and acute. The outer one is much larger and about twice as 

 long, scarcely tapered, often compressed, blunt at the tip, and some- 

 times bifid. It is rather larger than the two spines of the next 

 adjacent pair. In some large specimens many of the larger adambu- 

 lacral spines are slightly capitate or clavate. Distally they often 

 stand nearly all in one median row on each plate, but this does not 

 often occur on the proximal plates. 



Color, in life, variable, most frequently bright orange-yellow or 

 orange-red, sometimes pale lemon-yellow, not rarely purple. 



Mr. E. Desor (op. cit., iii, 1848, p. 11) not only states that this 

 species has the habit of carrying the eggs, but adds that : " On 

 removing the eggs from the mother's embrace, she was seen to 

 move at once directly towards and clasp them again." 



