go NATURAL HISTORY BULLETIN. 



and Astroloma, with simple arms, and Astrocnida with the 

 arms forked near the ends. 



Astrogomphus vallatus Lyman. 



Astrogomphus vallatus Lyman, Bull. Mus. Comp. Zool., I, 10, p. 350, 

 1869; | 111. Cat. Mus. Comp. Zool., VI, pi. I, figs. 16-18; Bull. Mus. 

 Comp Zool., V, 9, p. 236; op. cit. X, p. 229, 279; Lyman, Report Voy, 

 Challenger, Zool., Ophiuroidea, V, p. 271, pi. XLIV, figs. 10-12, 

 1882, anatomy. Nutting, Narrative, p. 171, pi., figs. 2, 2a. 



The larger specimens usually have five arm-spines on the 

 proximal part of the arm, but sometimes only four, or five and 

 four irregularly alternating. A very large one has six spines 

 on some of the basal joints, the extra one being external to 

 the others and smaller. The spiniform single tentacle-scale 

 of the first joint is often wanting on some of the arms. The 

 second joint usually has four spines (or tentacle-scales), in 

 form like those of the following joints. The disk has a defi- 

 nite marginal row of rough spinules; the interbrachial spaces 

 and most of the oral region appear smooth in alcohol, but 

 when partly dried have a fine tesselated appearance; when 

 quite dry these parts are covered with a close mosaic of 

 larger and smaller mostly flat granules, the larger ones being 

 somewhat conical. The cluster of spinules in the interradial 

 angles is pretty clearly circumscribed, but one spinule often 

 stands a little apart and more towards the mouth-angle. The 

 madreporic shield is small, roundish, and just outside one of 

 the groups of interradial spinules. 



Stations 28 and 29, off Sand Key, 116 fathoms, 40 ex- 

 amples; station 56, Pourtales Plateau, 200 fathoms, four ex- 

 amples; station 64, off American Shoal, no fathoms, four ex- 

 amples; station 62, 70 to 80 fathoms, two examples. 



It was taken by the "Blake" in many localities throughout 

 the West Indian region, in 88 to 337 fathoms. 



It is found clinging to branches of Gorgonella and other 

 gorgonian corals, which it imitates closely in colors. 



One large specimen from Station 56 has repaired extensive 



