HYALASCUS SIMILIS. 99 



Of other points in the spiculation I may put down the fol- 

 lowing notes, though these are in the main nothing but repeti- 

 tions of what I have already stated under //. sagamiensis. 



Farenchymalia, slender diactins of varying length (up to 

 25 mm. or more) and thickness (up tp about 175 /^) ; no hexac- 

 tins. Medium-sized diactins under the gastral layer often with 

 cruciately disj)Osed knobs at the spicular center. 



Hypodermalia, slender-rayed oxypentactins with bent para- 

 tangentials which may be 1 mm. long. 



Dermalia, pentactins, sometimes hexactins ; prickly all over. 

 Length of ray, 80-114 u. 



Oastralia, hexactins in which the free proximal ray may 

 attain a length of 285 ix; other rays 120-165 p. long. Eays 

 prickly but smooth at base. 



Oxyhexaster, hemihexactinose and often hexactinose. Diame- 

 ter, 90-125 II. 



All the spicules here remarked upon, let it be repeated, 

 essentially agree with those of H. sagamiensis in the manner of 

 their arrangement as well as in details of character. 



Finally, I regard it worth while to mention certain oxyhex- 

 asters which seemed to be in a state intermediate, so to say, 

 between the hemihexactinose and the hexactinose forms. Such 



looked by me in the specimen of the former ? If it was, H. simili-i at once loses its specific 

 status and slionld be combined with H. sagamiensis. However, careful re-examinations of 

 the preparations of tlie latter, partly newly made from a piece in my possession, have en- 

 tirely failed to reveal a second discohexaster form in addition to the one attributed to the 

 species in the text. So the matter stands thus: H. sagamiensis has a single discohexaster 

 form ; H. similis possesses the same in quite a limited number and, in addition to it, a 

 sec nd smaller form which occurs in moderate abundance. Whether with more specimens 

 in hand the difference indicated can be maintained as a specific distinction, can not be 

 foretold. Since anyway it seems impossible to base generic separation on that difiërence, it 

 becomes necessary to make a slight emendation in the generic diagnosis given on p. 87, 

 the last sentence on which sliould read " Discohexasters m one or two small forms witli 

 very tine terminals," instead of " Discohexasters in one small form", &c. 



