402 Transactions of the Society. 



small but powerful ; four anterior styles. Largest size of female 

 32G ft (y F in.) long by 145 /* (y^g in.) wide across the auricles. 

 Marine and in brackish water. 



Mr. John Hood, of Dundee, first discovered this marine and 

 brackish water species in the spring of 1886, in tide pools of the 

 estuary of the Tay, and gave a description and rough sketch of it 

 in the July number of Science Gossip of 1887. 



In the autumn of last year 1 obtained specimens from Great 

 Yarmouth, and subsequently also from brackish water pools near 

 Exmouth and Worthing, which have enabled me to make this 

 description and Mr. Dixon-Nuttall the accompanying excellent 

 drawing, fig. 17. Both the drawing and the well preserved and 

 mounted animals were identified by Mr. Hood, which was neces- 

 sary, as his rough sketch is deficient in accuracy. 



The budy is stout, cylindrical or barrel-shaped, widest in the 

 middle, tapering gradually posteriorly ; the foot is distinct, short, 

 tapering, and carrying two distinct broad and acute toes, slightly 

 shouldered on the outer side ; two distinct foot-glands are contained 

 in the foot. The head also is cylindrical, hardly wider than the 

 widest part of the budy. The auricles are comparatively small but 

 powerful; the head is truncate in front without any conspicuous 

 prominences. Two pairs of styles arise in front, the outer pair 

 from very small fleshy eminences. The vibratile cilia in front 

 have the usual arrangement in four regions. The mouth is ventral 

 in position, surrounded by the usual tactile tufts of seta* and circlet 

 of short stiff hairs. The eye is large, cervical, and consists of two 

 dark red closely apposed bodies or clusters of red granules. The 

 mastax is large, of usual Synchaeta shape and structure, and of 

 S. oolong a type with six broad, lancet-shaped teeth in each uncus. 

 The dorsal antenna protrudes on a dorsal eminence above the eye„ 

 and the lateral antennae are situated at the sides, slightly below 

 the middle of the body. 



The stomach is large, of usual shape, as well as the gastric 

 glands, ovary, lateral canals and contractile vesicle, all of which 

 are clearly indicated in Mr. Dixon-Nuttall's excellent figure. The 

 integument is fairly firm, showing more or less prominent trans- 

 verse and longitudinal folds, particularly on the dorsal side. 



In swimming, this Synchaeta moves rapidly, almost rolling in 

 the water like a barrel, without apparent aim ; it also spins a 

 thread from the toes to which it attaches itself occasionally. 



The eggs are nearly spherical, coloured slightly brown, and 

 78 fi (g^g in.) in diameter ; when laid they fall off at once, and are 

 not carried about. 



The male has been seen by Mr. Hood, who describes it as a 

 conical slender creature, 85 fi (300 i n -) m length. 



Habitat : in sea- water and brackish tide pools, near Dundee, 

 Great Yarmouth, Exmouth, Worthing, and probably all round the 

 coast. 



