ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 725 



subsequent formation of an entirely closed sac : the breakdown of the 

 larval organs ; and the partial absorption of the muscle-fibres by 

 phagocytes. 



Echinoderma. 



Deep-sea Starfishes.* - - Rene Koehler reports on the deep-sea 

 Asteroidea collected by the ' Investigator ' in the Indian Ocean. The 

 collection includes at least thirty new species and five new genera- 

 Johannaster, Phidiaster, Sidonaster, Circeaster, and Lydiaster. 



The genera Circeaster and Lydiaster are very specialised members of 

 the family Antheneidea? ; Johannaster stands by itself among the 

 Plutonasterideffi ; the other two new genera are less specialised, but 

 exhibit curious combinations of characters. 



Statocysts of Synaptids.j — Siegfried Becher has made observations 

 on these organs in living specimens of Leptosynapta b&rgehsis, and 

 finds evidence that they serve to make the animal aware of the position 

 of its body and of its movements. 



Non-Muscular Articulations in Crinoids.J — A. H. Clark discusses 

 this difficult subject. " The non-muscular articulations in the crinoid 

 arm. synarthries, or bil'ascial articulations, and syzygies, have an entirely 

 different effect upon the arm structure than have articulations possessing 

 muscle bundles, straight or oblique muscular articulations." He con- 

 trasts the two modes of articulation in detail. He is convinced that a 

 detailed and careful study of the articulations and articular faces in the 

 fossil crinoids is one of the best lines of procedure in the elucidation of 

 their systematic relations. 



Crinoids of Tennessee. §— Elvira Wood has made a critical summary 

 of Troost's unpublished manuscript (1849) on the Crinoids of Tennessee 

 — a valuable monograph, which has had a curious history. 



Coelentera. 



Revision of Lamouroux's Collection of Hydroids. |] — Armand 

 Billard has revised the collection in the Botanical Institute at Caen, and 

 done the useful service of indicating what the various types would be 

 called nowadays. 



New Leptomedus8e.1T — H. B. Torrey reports on a collection from 

 the San Diego region, consisting of eleven species, all new except one. 

 Two new genera are required — Scrippsia, which is distinguished from 

 its nearest relative Poly orchis by the gastric peduncle and the absence of 

 pinnately arranged branches of the radial canals distal to the gonads, 

 and Tiaropsidium, which is near Tiaropsis, but with tentacles of two 

 kinds. 



* An Account of the Deep-sea Asteroidea collected by the Royal Marine Survey 

 Ship ' Investigator.' Calcutta, 1909, pp. 1-143 (13 pis.), 

 t Biol. Centralbl., xxix. (1909) pp. 413-25 (12 figs.). 

 t Amer. Nat., xliii. (1909) pp. 577-87 (14 figs.). 

 § U.S. Nat. Museum, Bull. 64 (1909) pp. 1-159 (15 pis.). 

 II Ann. Sci. Nat., ix. (1909) pp. 307-37 (10 figs.). 

 1 Univ. California Publications (Zoology) vi. (1909) pp. 11-31 (11 figs.). 



Dec. 15th, 1909 3 C 



