584 SUMMARY OF CURRENT RESEARCHES RELATING TO 



considerably higher proportion of sexual females in the starved families. 

 But on the evidence of all the experiments the author concludes that 

 the higher proportion of sexual forms in the starved families is due, not 

 to the lack of food, but to absence of chemicals which, in the well-fed 

 families, prevent the appearance of the sexual forms. 



Echinoderma. 



Experiment with Sea-urchin Ova.* —Tad. Garbowski has tried to 

 make eggs of Paracentrotus lividus unite with those of Asterias glacialis, 

 and in doing so observed that the cells sometimes show centrosomes 

 with an extraordinary clearness, as if there had been intra-vitam 

 staining. The two kinds of eggs were shaken together in a centrifugal 

 machine, and it was observed that in the sea-urchin ova, some of which 

 had segmented, there were large bright red centrosomes, just as if they 

 had been stained. This is due, however, to a peculiar aggregation of 

 the characteristic pigment of the Paracentrotus ova, which occurs as a 

 sub-equatorial girdle or diffusely. 



Indian Ocean Shallow-water Asteroids.f — Rene Koehler gives an 

 account of the littoral starfishes in the Indian Museum, Calcutta — 

 67 species, of which no fewer than 28 are new. The new species belong 

 to the following genera : — Luidia, Astropecten, Dorigona, Goniodiscus, 

 Anthenea, Pentaceros,Asterina, Disaster ma, Nepanthia, Chsetaster, Fromia, 

 Ferdina, Oyhidiaster, LincTcia, Nardoa, and ScMerasterias. The author 

 has paid particular attention to the genus Pentaceros. 



Coelentera. 



Indian Ocean Alcyonaria. — J. Arthur Thomson and E. S. Russell J 

 report on a collection of Axifera made by J. Stanley Gardiner. There 

 are 50 species, of which 11 are new. The following are some of the 

 points of interest. A variety of Plwnarella delicatissima, previously 

 obtained from the west coast of Patagonia, was found at Providence. 

 Interesting new species of Calicogorgia have afforded material for 

 making a clearer distinction between this genus and the nearly related 

 Anthogorgia. In Calicogorgia rigida sp. n. the polyps contained numerous 

 embryos, about 1 mm. in diameter. The somewhat divergent Echino- 

 gorgia rarnosa sp. n. seems to connect its genus with Anthogorgia. The 

 species Bebrgce mollis Philippi should include B. philippi Studer and 

 B. studeri Whitelegge ; it is found from the Mediterranean to Funafuti. 

 Many striking examples of " convergence " and of colour-variability are 

 seen in the collection. An artificial key is given for the species of the 

 genus Acis. 



J. Arthur Thomson and Doris L. Mackinnon§ report on the 

 Stolonifera, Alcyonacea, Pseudaxonia, and Stelechotokea, of the same 

 collection, dealing with 76 species, of which 13 are new. A remarkable 



* Bull. Internat. Acad. Sci. Cracovie, 1910, pp. 95-110 (8 figs.). 



t Echinoderma of Indian Museum, pt. vi. (Calcutta, 1910) 191 pp. (20 pis.). 



% Trans. Linn. Soc. London (Zool.) xiii. (1910) pp. 139-64 (4 pis.). 



§ Tom. cit., pp. 165-211 (5 pis.). 



