610 SUMMARY OF CUBEENT EESEAECHES EELATING TO 



exhibited near the beginning (epacme) of its history, and there is a 

 progressive restriction of variability to characters of lower and lower 

 taxonomic value, till finally only characters of no physiological import- 

 ance are affected. A corollary of this law of progressive restriction of 

 variability is the rapid production of new types near the beginning 

 (during the epacme) of a phylum. The notion that species are formed 

 by the very gradual increment of selected variations certainly does not 

 suit the case of Platystrophia. Given a new and vigorous stock in a 

 favourable environment, the initiation of new species may take place with 

 great rapidity. The history of the genus affords fine examples of 

 morphological equivalence and hoinceomorphy. The greater part of 

 the history of Platystrophia is progressive, but a few genuinely retro- 

 gressive forms occur, which are interpretable as due to the acceleration 

 of gerontic changes. The general law is well illustrated, that the older 

 a character, the more persistent it is. 



Echinoderma. 



Regeneration of the Body of a Starfish.*- — Sarah P. Monks cut 

 •arms of Phataria (Linckia) faseialis at different distances from the 

 disc, and a number of single rays produced new bodies. The free ray 

 made a new body and the rest of the starfish produced a new ray, and 

 there was very little difference in the rate of growth of each, and no 

 definite place for breaking. The manner of growth is as follows : — The 

 cut edges heal and draw down towards the oral side, then small knobs 

 appear at the end which grow into rays in which the ambulacral furrow 

 soon appears, with the small mouth in the centre of the rays. 



Coelentera. 



Excretory Cells in Hydroids.j — A. Billard describes granular amoe- 

 boid ectodermic cells in various calyptoblastic hydroids (Campanularia, 

 Obelia, Plumularia, &c), which do not form perisarc (as Jickeli sup- 

 posed) and do not contain reserves, but are apparently receptacles for 

 waste-products. The " excretory cells " are especially abundant at the 

 extremities where growth is rapid, and in old colonies or parts. The 

 granules are not eliminated. 



Some New and Rare Corals from Funafuti.! — GT. C. Bourne gives 

 a figure of Lophohelia tenuis Moseley, once previously recorded from a 

 ' Challenger ' dredge in the Philippines. He describes and figures 

 Trochocyathus vasiformis sp. n. and T. hastatus sp. n., and indicates 

 how they differ from members of Moseley's genus Odontocyathus. 



Species of Corallium.§ — Kamakichi Kishinouye finds that the species 

 of Corallium are more numerous than has hitherto been supposed. He 

 describes five new species, — C. japonicum, C. boshuensis, C. sulcatum, 

 C. Jconojoi, and C. inutile. 



* Proc. Acad. Sci. Philadelphia, 1903, p. 351 (1 fig.), 



t Comptes Kendus, exxxvii. (1903) pp. 340-2. 



% Journ. Linn. Soc. (Zool.), xxix. (1903) pp. 26-37(2 pis.). 



§ Zool. Anzeig., xxvi. (1903) pp. 623-6. 



