18 ART. 7. 1. IJIMA : HEXACTINELLIDA, IV. 



22. Aulosaccus schuUei Ij. (Sagarai Sea). 



23. A, Ijimai (F. E. Sch.). {= Calycosaccus ijimai F. E. 

 ScH.). (S. of Alaska, 291 m.). 



24. A. mitsukurU It. (Sagami Sea). 



25. Asconefua^- sefnfmlense S. Kent. (N. Atlantic, 18o- 

 1170 m.). 



26. Trichasterina horealis F. E. Sch. (N. of Spitzbergen, 

 1000 m.). 



27. Aphorme hovt-ida F. E. Sch. (Off San Diego, Cal., 

 849 m.). 



28. Bathi/dorHs fimbriatus F. E. Sch. (N. Pacific, 4206 

 m.). 



29. B, stellatus F. E. Sch. (Messier Channel, S. Chile, 

 256 m.). 



30. B, lœvis F. E. Sch. (B. of Bengal, 3652 m.). 



31. B. unci fer F. E. Sch. (Galapagos Ts., 717 m.). 



32. B. Mpinosus F. E. Sch. (Pinguin Ts., 2926 m.). 



33. B. havAilifev F. E. Sch. (S. Mid-Pacific, 4270 m.). 



Differential Key to the Genera. 



(The numbers in piirenthesis refer to those of the above list). 



It. — "Witliout pentactinio hypodernialia. 



a'. — Body trnmpet-like or with »astral surface everted so as to form a large part of tlie 

 outer surface; always with long stalk. Discoliexaster in one small variety, or 



entirely wanting Avioehone F. E. Sch. (Nos. 19-21). 



/>'. — Body saccular or vase-like, witliout stalk. Discoliexaster in two (large and small) 



varieties Aiilomccus Ij. (Nos. 22-24). 



b. — With pentactinic hypodermalia. 



r;>. — Hexaster consists of oxyhexaster only (without discohexasler). 



a*. — Paratangentials of hypodermal pentactin, spiny. All oxyhexasters hexactinose. 



Aphorme F. E. Scir. (No. 27). 



6'. — Paratangentials of hypodermal pentactin, not spiny but smooth and rough at 

 ends onlv. Oxyliexasters, some or all normal- 



