WEST INDIAN STAEFISHES 105 



nmnber varies from less than three up to nine or more, on a 

 side, according to age. The largest number counted by me was 

 19 in one interradial arc on a specimen with radii 35™™ and 65™™. 



The tyipe has numerous conical dorsal spines, for they occur on 

 nearly all the radial and disk plates, but not on the marginals, 

 though some of these are swollen or somewhat tubercular. In 

 the type the penultimate superomarginal is a little larger than 

 those that precede it, but in others, equally large, they decrease 

 regularly in size. One or two distal pairs are usually in contact 

 medially. 



The dorsal plates are rather large, polygonal, with regular 

 granules. Most of them, except on small interradial areas and 

 near the tip of rays, are surrounded by numerous (10 to 12) 

 simple papular pores. Proximally, in adults there are, also, 

 small, interpolated, granulated plates between the larger radial 

 plates and between the papulae. 



On each of the distal adambulacral plates there is a single 

 large, obtuse conical spine, outside the furrow-series of slender 

 spinules. These spines are longer and larger than the more nu- 

 merous corresponding spines of the more proximal plates. There 

 are usually, in large specimens like the type, four stout, pris- 

 matic, blunt, crowded spinules on each plate, in the furrow- 

 series. 



This type specimen (Museum of Yale University) has a large 

 number of high, pincer-Hke fossate pedicellariae, with two slen- 

 der spatulate or spoon-shaped blades, and a slightly enlarged ar- 

 ticulating base ; the blades are sometimes straight, but often more 

 or less strongly curved to the right or left. The blades, when 

 fully expanded, rest in socket-like depressions of the plates, which 

 correspond in shape and curvature with the blades, so that the 

 two belonging to a pedicellaria with curved blades, form, when 

 taken together, a crescent-shaped or semicircular fossa, with a 

 round central pore and a wider rounded depression at each end. 

 Sometimes one or two granules exist close to the pediceUariae, 

 and when rubbed off the pits that they leave make the markings 

 on the plates more complex. 



Pedicellariae of this form are present on a large proportion of 

 the interactinal plates; on some of the marginal plates; on the 

 borders of the spiniferous dorsal plates, around the bases of the 



