396 Transactions of the Society. 



cavity ; the jaws are of usual Synchseta type, but extremely deli- 

 cate ; the unci have five or six teeth. 



The stomach is small, carrying two pointed gastric glands, and 

 the rounded ovary, lateral canals, and contractile vesicle are present 

 as usual. 



The dorsal antenna projects from a dorsal eminence a little 

 below the eye, while the lateral antennae protrude at the extreme 

 posterior and narrow part of the body, as in S. tremula. 



The integument is very soft, showing more or less distinct fine 

 longitudinal folds. When held fast in the compressor the animal 

 is very restless, contracts and contorts its body in all manner of 

 shapes, so that it can hardly be recognised under these conditions. 



In swimming the motion is slow and steady, the animal re- 

 volving on its longer axis as it proceeds, and now and again 

 suddenly changing its direction at right angles to its former course. 

 S. hitina does not anchor itself to a thread and revolve on the same 

 spot as does & tremula. 



The pretty sketch, fig. 6, has been drawn by Mr. F. E. Dixon- 

 Nuttall from life, and gives a good idea of its usual shape. 



In size, this is one of the smallest Synchaetse known, being 

 only 136 //, { Y \ 5 in.) in total length by 102 /j, (^q in.) wide at 

 the auricles, whilst smaller individuals are always present also. 



Synchseta tavina (Hood). 

 PL VIII. fig. 18. 



BIBLIOGRAPHY. 



Hood, John. — Synchceta tavinn. Inter. Journ. of Microscopy and Nat. 

 Science, 1893, pp. 382-3 (1 pi.). 



Spec. Char. — Body markedly cylindrical in shape, truncate in 

 front; auricles small; foot short, carrying two small, separated 

 toes ; eye cervical, usually appearing double ; the lateral antennae 

 situated in the lumbar regions. Size 254 ft ( T ^ in.) by 95 fi 

 (^L_ in.) wide at the auricles. In brackish water. 



Mr. John Hood also discovered this species in the tide pools of 

 the Tay in the early spring of 1893, and published an account 

 of it in the International Journal of Microscopy and Natural 

 Science for October of that year. 



The shape of the body is conspicuously cylindric, being scarcely 

 wider in front than at the side and somewhat compressed laterally, 

 then tapering gradually to the short foot and toes. The foot is in 

 a line with the ventral side of the body, and the toes are generally 

 carried turned upwards. At first sight it is hardly recognised as 

 belonging to the genus Synchceta, so unlike is it to the char- 

 acteristic cone-shape of nearly all the other species of this genus. 



