184 VERRILL 



ORTHASTERIAS GONOLENA Verrill, sp. nov. 



Plate LXVII (dorsal side) ; plate LXVIII, figure I (actinal side) ; plate LXIX, 

 figure 2 (portion enlarged) ; plate LXXXII, figures 3-3&, 4-40 (details). 



Rays five, of moderate length, rather stout, somewhat angular. 

 Disk small. Radii of the specimen figured, 8 mm. and 68 mm. ; 

 ratio, 1:8.5. Radii of a larger specimen, 13 mm. and 83 mm.; 

 ratio, i : 6.4. 



Dorsal spines rather long, tapered, obtuse, not much grooved or 

 fluted, well spaced. They form three rows, quite regular in the 

 smaller specimens, less so in the larger. The median row is distinct, 

 having more regular and more numerous spines, though they are not 

 longer. The spines stand singly on rather stout, alternate plates. 

 They are surrounded in the dry specimens by a large subbasal wreath 

 of small minor pedicellarias attached to the edge of a thick basal 

 sheath. Papular areas unequal; some are very small, others large, 

 with many small papulae. Superomarginal spines similar to the dor- 

 sals in size and form. They form a regular row, one to each alternate 

 plate. No intermarginal spines; interactinal plates are sporadic, 

 spineless, small, compressed, standing edgewise, scarcely visible 

 unless cleaned by potash. The integument is rather thick. 



The inferomarginal spines stand two to a plate, placed obliquely 

 in two rows, close to the adambulacrals, but with a row of small, 

 single papulae between. These spines are about as long as the supero- 

 marginals, but not so stout, and they are decidedly flattened dis- 

 tally. There is a wide, conspicuous intermarginal channel, in which 

 papular areas of small size alternate with the plates in a regular row. 

 In this lane or channel are also scattered erect, stout, wedge-shaped 

 pedicellariae of large size, often nearly as stout as the spines. The 

 lane is crossed by the long, stout, descending apophyses of the su- 

 peromarginal plates, which meet and overlap the ascending lobes of 

 the inferomarginals, without an intermediate ossicle. The alternate 

 spineless plates have equally large apophyses. The dorsal connec- 

 tive ossicles are stout, nearly as wide as the plates. 



The adambulacral spines stand obliquely, two to a plate, erect in 

 the type, nearly equal in length, the inner ones more slender, all 

 distinctly flattened and sometimes slightly grooved distally, except 

 the adoral ones, which are longer, more slender, terete or nearly so. 



The dorsal dermal pedicellariae are few on the type, wedge-shaped. 

 Some very large ones are found on the sides, as mentioned above, 

 and some of the same form and equally large are sometimes found 

 attached to the inner edge of the adambulacral groove, or to the bases 



