484 BihliograpMcal Notice. 



regarded eitlier as being derived from Ainpliidi.-^cophora by 

 loss of amphidisks, modification of" microliexactins into 

 hexasters, and higher development of the choanosom, or 

 simply as Hexasteropbora which have developed pinuli ; the 

 latter seems the more likely hypothesis. 



Specimens of Amphidiscophora would require to be fixed 

 suitably at the moment of capture, in order to show the 

 delicate contractile protoplasm with the spicules in situ. In 

 ordinary museum specimens I have invariably found the 

 tissues much contracted, leaving the bare convex distal heads 

 of the amphidi:?k3 exposed on the surface. 



BIBLIOGRAPHICAL NOTICE. 



Memoirs of the Indian Museum. — Yol. II. No. 2. An Account of the 

 Indian Cirripedia Peduncidata . — Part I. Fam. Lepadidae (sensii 

 stricto). Plates Yl.-Vil. By N. Annajjdale, D.Sc. Published 

 by Order of the Trustees of the Indian Museum, Calcutta. 1909, 

 Two Rupees. 



Dr. Axxandale has done much more than give a mere list o 

 species in this most valuable and interestiug memoir, for he has 

 touched upon many themes that deserve far closer attention than 

 they have hitherto received. 



Confiuiug himself in the present contribution to the Pedunculata, 

 he points out the difficulties of his task, owing to the fact that there 

 are few groups which afford so many or such perfect instances of 

 convergence or adaptive resemblance. With such material the 

 formation of a natural system of classification — a system based on 

 descent — is well nigh impossible. He gives some interesting 

 illustrations of this fact, selecting as the best example among the 

 Lepadidse Poecilasma hcempferi, which occurs in its typical form in 

 Japan and in the South Pacific, hut is represented by subspecies iu 

 several different parts of the Indian and Atlantic Oceans. 



Some extremely interesting facts on life-history are to be found 

 in Dr. Annandale's notes on the several genera herein described. 

 Thus, of the genus Dichelasjns he tells us that with one exception 

 the species thereof affix themselves on settling down in life to the 

 bodies of hard-shelled Crustaceans ; but the exception — D. (jrayi — 

 chooses the skin of sea-snakes. 



Space forbids more than a very brief notice of this most inf.er- 

 esting memoir, which should prove a very welcome addition to 

 carcinological literature. 



