ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 161 



to be. The names with which science has been burdened are the fol- 

 lowing : — Callidina quadridens, Hydatina monops, Mastigocerca flecto- 

 caudatus, Notommata pentophthalma, Planoventer varicolor, Mastigocerca 

 rectocaudatus, Dinocharis inornata, Diaschiza taurocephalus, Postclausa 

 minuta, Postclausa circularis, Colurus gracilis, Notlwlca regularis. 



Echinoderma. 



Structure of Echinus esculentus.* — H. C. Chadwick gives a fully 

 illustrated account of the main features in the structure and development 

 of this sea-urchin. In the vicinity of Liverpool he finds that it is car- 

 nivorous in habit, the intestine frequently containing shells of barnacles 

 and tubes of Serpulids. 



Pigment of Echinus esculentus.j — A. B. Griffiths finds that this 

 violet pigment is a lutein or lipochrome. It corresponds to the formula 

 C 16 H 12 N.,0 ; is soluble in alcohol, ether, benzine, acetic acid, &c. ; and 

 changes into leucine and formic acid when boiled for a long time with 

 strong mineral acids. 



Regeneration in Ophiuroids4 — C. Dawydoff has studied the re- 

 generative phenomena in a species of Amphiura, with which he compares 

 several other forms. After amputation there is a period of phagocytosis ; 

 the first sign of regeneration is a proliferation of the skin over the cut 

 surface. The ambulacral canal grows out from the old canal ; the meso- 

 derm of the new bud arises in greater part (mesenchyme) from amoeboid 

 cells, and from the separation of connective-tissue from the internal layer 

 of the skin of the bud. The coelom is continued from the old coelom ; 

 the epineural canal is derived from the schizocoel formed by a separation 

 of the nerve-strand from the epithelium, and has thus no ontogenetic 

 relation to the pseudohremal canal which is derived from the enterocoel. 

 The nerve-strand is formed afresh from the ectoderm. Tube-feet arise 

 by evagination of the lateral parts of the ambulacral canal, and the 

 nerve-strand shares in their development. In a general way, the re- 

 generative processes are in harmony with those of ontogenetic develop- 

 ment. 



Development of Agaricocrinus.§ — Mary Klem concludes that the 

 first plates to be formed ventrally were the six orals. The basals 

 appeared simultaneously. The next step was the formation of a series 

 of smaller pieces around each oral ; but in no two cases is the ring com- 

 posed of the same number of pieces, or of pieces of the same size. " The 

 variations in the size, shape, and number of these plates, in all proba- 

 bility, depended upon the quality and the quantity of food, the amount 

 of light, and the nature of the surroundings." Intervening pieces, also 

 very variable, were formed at a later period, as the necessary material 

 could be produced. The number of species based on variations is 

 absurdly large ; it can be readily reduced from forty-two to ten. 



* Trans. Liverpool Biol. Soc, xiv. (1900) pp. 298-325 (5 pis.). Also published 

 as Memoir III. of Liverpool Marine Biology Committee, 

 t Comptes Kendus, cxxxi. (1900) pp. 421-2. 



% Zeitschr. wiss. Zool., lxix. (1901) pp. 202-31 (2 pis. and 3 figs.). 

 § Trans. Acad. Sci. St. Louis, x. (1900) pp. 167-84 (4 pis. and 1 fig.). 



April 17th, 1901 M 



