SHALLOW- WATER STARFISHES 221 



the smaller ones are rounded or elliptical. All are crowdedly cov- 

 ered with very numerous fine and slender, rather long, spicule-like, 

 equal spinules. 



The upper and lower rows of marginal plates are easily recog- 

 nizable, the lower ones larger. They are distinctly larger than the 

 adjacent dorsals, but bear the same kind of slender spinules. They 

 are transversely oblong-elliptical in form, becoming more quad- 

 rangular distally, where the two rows are contiguous and similar. 

 Proximally they diverge strongly and are separated at the base of 

 the rays by two or more short rows of intermarginal plates, similar 

 in form to the supramarginals, but rather smaller; of these, the 

 middle row may extend to about the mid-length of the ray. 



A single row of smaller interactinal parapaxillae (sometimes 

 double) intervenes between the lower marginals and adambulacrals. 

 They are somewhat quadrangular or roundish in form and extend 

 nearly to the tips of the rays ; they bear fine spinules, like those of the 

 marginals. The papulae between the marginal and peractinal plates 

 are rather large and mostly stand isolated. 



The adambulacral plates bear an unusually large number of 

 spinules, often twenty-five to thirty or more. These spinules are 

 slender, erect, and closely crowded, decreasing in size and length 

 from the margin of the groove outwardly; the outer ones are 

 similar in size to those of the adjacent interactinal plates. They 

 mostly stand in three or four radial rows on each plate, while there 

 may be six to nine in each transverse row. The two or three standing 

 at the margin of the groove are distinctly larger than the rest; and 

 next to these is a second oblique row, usually of three, that are 

 smaller, but distinctly larger than the third row. The single furrow- 

 spine is short, acute, and hardly reaches the margin. The adambu- 

 lacral spines are all slender and not clavate. 



Adoral and epioral spines numerous, crowded, scarcely larger 

 than adjacent adambulacrals, and similar in form, seven to nine in 

 each marginal series. 



The general appearance of this variety is similar to that of a 

 stout-rayed H. leviuscula or sanguinolenta, but it is peculiar in hav- 

 ing unusually large numbers of crowded and slender adambulacral 

 spines on each plate.* A larger series of specimens shows apparently 

 intermediate forms between this and leviuscula. 



* Dr. Clark's diagrammatic figure (pi. iv, fig. i) represents them as much 

 more regular and equal than they actually are. The exterior ones are rep- 

 resented as about as long as the inner or marginal ones, but they are not 

 half as long. 



