ZOOLOGY AND BOTANY. MICROSCOPY, ETC. 301 



They adhere tenaciously by an apparatus having the function of a sucker 

 to the filaments of the gills or to the walls of the branchial chamber, 

 and are thus not liable to be swept out by the respiratory current or 

 dislodged by the movements of the podobranchs. With cilia only 

 developed ventrally, they glide along in close contact with the sub- 

 stratum, so that they can instantaneously anchor themselves when any 

 movement takes place that might displace them. 



New Terrestrial Nemertean.* — W. J. Dakin describes Geonemertes 

 deiidyi sp. n., from the Darling Hills, near Perth, Western Australia. 

 The length of the mature female is about 15 mm. when crawling. The 

 colour is brown - pink, with two dorsal and somewhat posterior 

 longitudinal bands of chocolate-brown. The 16 or 17 eyes are in four 

 groups. Lateral organs are well developed, opening by characteristic 

 ciliated cephalic pits on the ventral surface at the anterior end. The 

 mouth opens into the rhynchodseum. The sexes are distinct. The 

 cephalic gland does not seem to be well developed. In other structures 

 the new form agrees well with 0. australiensis. The specimen was 

 found under a small los;. 



Echinoderma. 



Behaviour of Comatulids.t — Hubert Lyman Clark found twenty- 

 two Comatulids at Maer, the largest of the Murray Islands, at the 

 northern end of the Great Barrier Reef. They exhibit complex and 

 variable reactions, and important differences are shown in the modes of 

 locomotion and feeding. Many Comatulids, especially the large 

 multibrachiate species, are very sluggish, and the members of the 

 family Comasteridae do not swim, but only creep about by using the 

 arms. Comatulids of the families Stephanometrida3, Mariametridas, 

 ColobometridtB, and Antedonidfe, although ordinarily inactive, are good 

 swimmers, and creeping is not the usual method of locomotion. It is 

 doubtful if, under unchanged conditions, Comatulids move about to 

 any important extent, but it is certain that local changes can, and do, 

 bring about considerable alteration of position and possibly real 

 migrations. 



Comatulids at Maer feed on living Algge and some Protozoa, 

 presumably swept in by the ciliated furrows. All are negatively 

 phototactic. They are markedly susceptible to heat, even to an 

 increase of 2°. They showed no response to altered salinity. Their 

 reaction to strong solutions of magnesium sulphate is noticeably 

 different from that of other Echinoderms. Reactions to strong alcohol 

 or formalin are marked and well defined, and normally follow a regular 

 sequence. Reactions to impure sea-water, presumably to the GO.^, are 

 slow but sure. An excess of impurity soon produces inaction, followed 

 by disintegration. 



* Proc. Zool. Soc, 1915, pp. 557-70 (1 fig.). 



+ Papers Dept. Mar. Zool. Carnegie Inst. Washington, viii. (1915) pp. 99-125. 



June 2 1st. 1916 Y 



