ART. 12 HEXACTINELLID SPONGES OKADA 77 



broadest part of the body are nearly the same as those of the type, 

 but the osculiim is somewhat oval in form, measuring 67 mm by 

 45 mm. 



The species here described as new is unquestionably a very near 

 relative of A. schulzel Ijima and A. albatrossi, new species. It can 

 scarcely be said to differ from these species so far as the categorical 

 forms of the spicular elements are concerned; but in the details of 

 the characters I find in all individuals referred to it certain con- 

 stant peculiarities that I think maj' be considered to be of sufficient 

 specific value. 



AULOSACCUS FISSURATUS SHIMUSHIRENSIS, new subspecies 



A tolerably large fragment (holotype, U.S.N.M. No. 22046) 

 was obtained from a deptli of 229 fathoms southeast of Shimushir 

 Island, Kuriles (Station 4803). 



/Spiculafiofi. — The hypodermalia and hypogastralia are pentac- 

 tins and diactins. The pentactinic forms appear f requenth^ and are 

 not so great in size. They are provided with paratangentials 130,u. 

 in length and with an unpaired proximal ray 680;u. to 2,500;u, long. 

 The surface of the ra37s is sparsely microtuberculated all over. The 

 rays taper slightly toward the rounded or conically pointed ends, 

 the surface of which is not so prominently tubercled as that occur- 

 ring in other members of the genus. The diactins are generally 20ju, 

 in breadth and are less than 180/a to 300/a in length. They taper very 

 slightly toward both conically j^ointed ends; the surface is sparsel}-- 

 tubercled. The center of this spicule is frequently marked externally 

 by a conspicuous swelling. 



The parenchymalia are all slender diactins in loose, feltlike ar- 

 rangement or grouped together into moderately thickened bundles. 

 The principalia may attain a length of 9 mm or more and a breadth 

 of 45/A at the middle; they taper gradually toward the rough and 

 shar25ly pointed ends. 



The dermalia are predominantly stauractins in which the atro- 

 phied fifth ray is frequently indicated by a gentle swelling on the 

 distal side of the paratangential cross. The axial length measures 

 170/A to 200/A and is 8//, to 12/i thick at the base. For the greater part 

 of their length they maintain a nearly uniform thickness. Besides 

 this form, occasionally they are represented by pentactinic forms. 

 The paratangential rays, as measured from the spicular center, are 

 75^ to lOOfj. long, and an unpaired proximal ray measures 92^,1 long 

 and 5fx broad at the base. The thickness of all the rays is nearly the 

 same, but decreases very slightly toward the rounded tips. Their 



