60 PEOCEEDINGS OF THE NATIONAL, MUSEUM vol.81 



always much thicker than the inner half, nearer the gastral surface, 

 which is quite gradually attenuated to a pointed end. The spines 

 are projected first in horizontal transverse directions and then are 

 bent backward. 



Besides this distinct uncinate, there occasionally occurs a small 

 uncinatelike spicule. It is usually 300/^ long. The distal end is some- 

 what extended in a lobelike manner, measuring 25/x, in breadth and 

 is then gradually tapered toward the conically pointed end, which 

 is 8ju, in breadth. The surface is roughened by densely distributed 

 microtubercles at the end of the spicule but elsewhere is quite sparsely 

 roughened by microtubercles. 



Of the spicules irregularly scattered throughout the parenchyme 

 I have found only one kind of ony chaster. It is 40/x to 80ft in diameter. 

 From each short principal (6ft long as measured from the axial 

 center) there arise two or three fairly thick, nearly straight, and 

 strongly divergent terminals. The finely attenuated end of these 

 bears a whorl of two or three fine backwardly arched minute claws. 

 The surface of the terminals is sparsely covered all over with minute 

 pointed microspines directed backward. 



The chief distinguishing characters of this species are: (1) The 

 uncinate is very robust in form, with large, short barbs; (2) 

 the small uncinate is distributed irregularly and is rarely found in 

 the dermal layer; (3) microscleres usually consist of one kind of 

 onychaster, measuring 40/a to 80ft in diameter and rarely of a normal 

 oxyhexaster. 



The present species is somewhat allied to the members of the 

 ApkrocalUstes group but differs from them by the existence of the 

 gastral hexactinic pinules together with the diactins. 



INDETERMINABLE APHROCALLISTES 



There is in the collection a fragmentary specimen, probably refer- 

 able to ApkrocalUstes. Since it is badly macerated, it can not be 

 more fully determined. It was taken at Station 5090 (entrance to 

 Uraga Strait between Jogashima and Okinose), and consisted of 

 small fragments of a thin-walled skeletal tube. 



Tribe LYSSACINOSA Ijima, 1927 



Family LEUCOPSACASIDAE Ijima, 1903 



Genus CHAUNOPLECTELLA Ijima, 1903 



CHAUNOPLECTELLA SPINIFERA Ijima 



Chaunoplectella spinifera Ijima, Journ. Coll. Sci. Imp. Univ. Tokyo, vol. IS, 

 art. 1, pp. 71-77, pi. 5, figs. 14-17 ; pi. 6, figs. 1-8, 1903. 



I have discovered in the collection a fairly large colony that is 

 unfortunately incomplete, lacking parts of the lateral wall. Though 



