440 ECHINODERMS OF THE BRITISH ISLES 



Ad. p. 292. Genocidaris. A new species of this genus was 

 dredged by the " Talisman " at the Canaries, 30 m. It differs 

 from G. maculata mainly in the smaller size of the anal plate, 

 in the ambiilacral midline being sunk, in its apical part, and in 

 its splendid red colour. Whether there is any prospect of 

 finding this species within the British area it is impossible to 

 say at present. A description of this species will be given by 

 the author in a note on the P^chinoids of the " Talisman " to 

 be published in the Bull, du Mus. d'Hist. Nat., Paris, 1927. In 

 this note will also be found some information on the characters 

 of Hygrosoma uranus. (Of. p. 286.) 



Ad. p. 313. The larva of Strong ylocentrotus dro- 

 BACHiENSis. According to information kindly furnished by 

 Dr. S. R/unnstrom, Bergen, this larva, in its I. stage, is character- 

 ized by having a rudimentary recurrent rod, much as in the 

 larva of Paracentrotus lividus (Fig. 177, h). The shape of the 

 body rod appears to vary rather considerably, being generally 

 somewhat irregularly widened, much as in Psammechinus 

 miliaris (Fig. 148, 1), more rarely simply club-shaped, as in Fig. 

 148, 4. The main breeding season is January-February. (Dr. 

 Runnstrom's researches will be published in Nyt Magazin for 

 Naturvidenskaberne, Oslo, 1927.) 



Ad. p. 326. Plagiobrissus Costae. This species has 

 actually been found in the Atlantic. The author, having recently 

 had the opportunity of examining the type-specimen of Rhahdo- 

 hrissus Perrieri Bernard from the "TaHsman", finds it to be 

 identical with the Mediterranean Plagiobrissus Costae. It was 

 taken off Cape Bojador, 782 m. 



Ad. p. 344. Pourtalesia. It appears that two more 

 species of this genus occur in the deep sea of the N.E. Atlantic, 

 there being in the material collected by the " Talisman " two 

 fragments, one of which appears to be the true Pourtalesia 

 miranda, the other a large species probably related to P. carinata. 

 (Cf. the author's paper in Bull, du Mus. d'Hist. Nat., Paris, 1927.) 



ILLUSTRATIONS 



All those figures for which no source is given are original 

 drawings or photos, made specially for this work. 



