234 bulletin: museum of comparative zoology. 



SALENIDAE Agass. 



Salenia miliaris A. Ag. 



Sahnia miliaris A. Agassiz, 1898. Bull. M. C. Z., 32, No. 5, p. 74 ; Plate 2, 

 Figs. 2-4. 



Small specimens of this Panamic species were collected at the following 

 stations. 



Station 4060. Off Alia Point Light, N. E. coast of Hawaii, 759-913 fathoms. 



" 4125. Off Kalmku Point, Oahu, 963-1 124 fathoms. 



" 4181. Off Hanamaulu, Kauai, 671-811 fathoms. 

 Four specimens. 



Salenia crassispina A. Ag. and Clark. 



This species, although closely related to the preceding, is easily distinguished 

 by the primary radioles which are remarkably stout, and although distinctly ver- 

 ticillate, are quite smooth. In miliaris, the greatest thickness of a radiole is 

 much less than the diameter of its milled ring, while in crassispina the diameter 

 of the spine is fully equal to, and may exceed that of its milled ring. The species 

 is further remarkable for the comparatively slight depth at which it was taken. 



Station 4045. Off Kawaihae Light, W. coast of Hawaii, 147-198 fathoms. 



One specimen. 



ARBACIADAB Gray. 

 Habrocidaris A. Ag. and Clark. 



This genus is established for Podocidaris scutata A. Ag. of the West Indies, 

 and for the following closely related species from the Hawaiian Islands. 

 Although quite similar to Podocidaris A. Ag., and even more so to Pygmaeoci- 

 daris D6d. } it may be readily distinguished from both by the very thin and delicate 

 test, the regular and very slightly indented actinal system, the close plating of the 

 entire buccal membrane, and the distinctly triangular primary radioles. 



Habrocidaris argentea A. Ag. and Clark. 



This species is closely allied to H. scutata A. Ag. from Santa Cruz (580 fms.). 

 It is at once distinguished by the much larger abactinal system, the different 

 shape of the ocular plates, and the distinctly pentagonal actinal system. The 

 single specimen taken is 11.5 mm. in diameter, with the abactinal system 7 mm., 

 the anal system 2 mm., and the actinal system 6 mm. Unfortunately all the 

 primary radioles are broken and only the basal portions of a few remain attached 

 to the test. These radioles are triangular in cross-section and the three edges, 

 though rounded, project conspicuously from the solid axis. The test is silvery, 

 tinged with brown, while the primary radioles were evidently white. 



Station 3973. Near French Frigate Shoal ; 23° 47' 10" N. — 166° 24' 55" W. ; 

 395-397 fathoms. 



