16 AKT. 7. 1. IJIMA : HEXACTINELLIDA, IV. 



The arcliGeocyte? are as usual deeply stained and on the 

 whole somewhat larger than trabecular nuclei. They do not 

 exceed ok p. in diameter. Though sometimes found isolated, they 

 more commonly occur in loose or compact groups varying greatly 

 in dimensions, always among, and on the outer side of, tlie cham- 

 hers. Many of the groups arc of a quite conspicuously large size 

 (PI. T.. fig. 9). 



B. ROSSELLINiE. 



Pentactinic hypodermalia generally present ; ex- 

 ceptionally wanting. Gastralia, liexactins; exceptionally 

 pentactins. Parenchymalia, chiefly diactins and includ- 

 ing medium-sized or small liexactins, or exclusively 

 diactins. Hexasters consist as a rule of oxyhexasters 

 and discohexasters ; the latter often in more than one 

 variety, but may be totally absent; lacking both stro- 

 1)1 loplumicome and discoctaster. 



The following is a list of all the genera and species which 

 1 consider to make up the subfamily as it stands at present. 



1. Jio>iHfUa aniavvtlca Carter. { — Acantkamm gro^mlaria 

 Y. E. 8eh.). (S. of Kerguelen Is.; SE. of Prince Edwards 

 Is.; Possesion Is.; 2-j6-ü49 m.). 



2. //. <Jnbîn (F. E. ScH.). (Ö. of Puerto Bueno, 732 m.). 

 ;î. //. }(irorifx<r Tops. (Western Antarctic, 450-569 m.). 



4. /.'. iiu<hi Tors. (Western Antarctic, 430 m.). 



5. Scf/phidffmi sepfenfrioiiale F. E. 8cH. (N. of Spitz- 

 bergen, 1000 m.). 



