OPHIUROIDEA OF THE BAHAMA EXPEDITION. 75 



Tooth-papillae about six, in a biserial group at the end of 

 the jaw, small and conical; two or three similar mouth-pa- 

 pillae on each jaw-margin, rather irregularly arranged, and 

 others higher up in the slits. On the first joint the tentacle- 

 pores are without scales or spines; on the second they some- 

 times have a single, very small one; on the third there are 

 either two or three small spiniform ones; on the fourth usually 

 three in each group, of which the inner is longest; on the fifth 

 joint, opposite the edge of the disk, there are three, the inner 

 or lower one being much longer and more spiniform than the 

 others, which have claw-like hooks on the lower side. 

 Farther out the number increases to four, and finally to six, 

 beyond the middle of the arm. The large, lower one is 

 about as long as a joint, blunt, and rough on the inside, on 

 the basal joints, but farther out it becomes obtuse and its dis- 

 tal part bears ten, twelve or more small glassy hooks, in two 

 or more rows (figs. 4, \a, 4^) ; those of the upper series are 

 all changed to claw-like hooks, the lower often with two or 

 three glassy points; they are attached to a transverse row of 

 prominent tubercles on the side arm-plates (figs. 4a, 4$, 4c). 

 Still farther out the lower spine is reduced to a claw, with 

 two or three points (fig. 4^). Near the tip of the arm there 

 are only two or three hooks in each row. 



Diameter of \disk of type, 15 mm; of arm at base, 4 mm; 

 length of arms, broken, 100-fmm. 



Station 16, off Havana, 200 fathoms. 



This species resembles A. loveni in appearance. The lat- 

 ter has the smaller arm-spines more nearly equal, shorter and 

 less strongly clawed; the lower one is more conical and the 

 roughnesses are not so claw-like on the basal joints. To- 

 ward the base of the arm there may be four or five slender, 

 tapered, nearly equal, divergent spines, but they all change 

 to claws distally. The mouth and tooth-papillae are fewer, 

 smaller, and less acute. 



A. locardi Koehler,* from the eastern Atlantic, in 17 10 m. 



*Rev. Biol, du Nord de la France, vol. VII, p. 34, 1895. 



