428 ON THE FAUNA AND BOTTOM-DEPOSITS NEAR THE 30-FM. LINE 



numerous as on the typical coarse gravel and sand of Ground IX. 

 The scarcity of hydroids may be due to the disturbance of the deposit 

 by periodic wave action, the existence of which, as pointed out above, 

 is also shown by the rounded and polished quartz grains. One of the 

 characteristic features of the fauna is the presence of large specimens 

 of Polycarpa varians attached to the gravel. CaryoiJhyllia Smithii is 

 plentiful on shells and Sarcodictyon catc7iata is also not uncommon. There 

 are few branched polyzoa, but incrusting forms on shells are numerous. 

 Wandering species. The presence of I'orania pulvilhts in considerable 

 numbers, and of Luidia Sarsi in small numbers, must be regarded as 

 characteristic. Ophioihrix fragilis is plentiful, but Ophiura ciliaris, 

 though generally present, is never numerous. Echinus esculentus and 

 £. acutus are not uncommon. Pectcn opercularis was very numerous 

 in some hauls, but scarce in others, the abundance of A. (jlacialis and 

 A. o^ubcns varying with that of the mollusc. Two or three specimens 

 of Pccten maximus were present in each haul, and must be considered 

 as one of the characteristic features of the ground. Crustaceans were 

 not numerous ; the species represented were those typical both of the 

 fine sand and of the coarse gravel. 



Considering the fauna of this ground as a whole, one may regard it 

 as composed of four elements, viz. (1), a fauna of its own, represented 

 by an abundance of Folycarpa varians, Porania pulvilhis, Pecten oper- 

 cularis, Cardiuni norvcgicum, Echinus esculentus, and E. acutus; (2) 

 many species found on the coarse gravel grounds, c.^., Ophiothrix fragilis 

 (abundant), Ohaetopterus variopedatus and its associates, Ehalia tumefacta 

 and tidjerosa ; (3) species characteristic of the clean shell gravel of the 

 neighbouring Ground XVI., e.g., Spatangus purpureus, Sarcodictyon 

 catenata ; (4) a few immigrants from the fine sand grounds, e.g., 

 Sertularella Gayi (scarce), Astropecten irregularis (an occasional small 

 specimen only), Ophiura ciliaris, and Ascidiella scabra. 



List of Species. Ground XIV. 



POHIFERA. 

 Snberites domuncula. 

 Cliona celata. Common, boring sliells. 



Hyduozoa. 

 Hydractinia ecliinata. In 73 only. 

 Clytia Johnstoni. On hydroids in 73. 



Campanularia Hincksii. On liydroids and 



on sliells. 

 Lafoea duniosa, vnr. rolnista. Recorded 



in 58 only. 

 Halci'iiini lialcciiiuiu. Fairly abnndant 



on Chnriojilrriis tubes 



and on sliells. 



Halecium Beanii. Small quantity in 59 

 only. 



,, labrosuin. One colony in 73. 



Sertularella Gayi. Small quantity only. 



,, polyzonias. Small quantity 



only. 



Sertularia argentea. A little in 35 only. 



llydrallmania falcata. A few colonies 

 only. 



Aiitcinnilaria antenniiia. A few colonics 

 only. 

 „ raniosa. A few eolnnies 



only. 



