SYNCH^TA TAVINA. 383 



are similar to the other species of the genus. I noticed that the 

 stomach of all the specimens I have examined were packed full of 

 a brownish matter. 6". tavina is a vigorous swimmer. Its motions 

 are zigzag or in spiral circles. I have never witnessed it indulging 

 in spinning round on its own axis and occasionally remaining 

 steady in the field of view, as is the habit of its fresh-water sister, 

 S. tremiila, but it always appeared dashing on at a rapid speed. 



I have never observed a single specimen carrying its eggs at its 

 foot — a practice which I have frequently observed in S. tremula. 



It is to me a very remarkable fact that I have only found this 

 creature in any considerable numbers at high water on spring tides ; 

 and although I have repeatedly trawled for it at high water at neap 

 tides, I have seldom found a half-dozen specimens. But when 

 spring tides came round, during March and April, it was found in 

 great abundance. This phenomenon I cannot explain, except it 

 be that, like the herring, S. tavina always keeps in shoals. 



Occasionally I have found it associated with Synchceta haltica, 

 Ehrn. ; Pterodina dypeata^ Ehr. ; Distcmvia raptor^ Gosse ; Diglejia 

 sutla, Gosse ; and invariably with Notholca thelassica, Gosse ; 

 Notholca schapha^ Gosse ; N'otholca Hoodii^ Western ; and with 

 varieties of Entomostracons, Infusoria, and Marine Diatoms of 

 various forms, most especially the Pleurosigma angulatum and 

 P. elongaUim ; while the delicate Amphiprora constricta was always 

 present in the sediment. 



The male has not yet been observed. A few females were 

 observed vvith ephippial eggs within their body-cavity, which 

 clearly indicated that the male had been present a short time pre- 

 viously, but had escaped observation. 



The length of fully-developed adults is from one-seventieth to 

 one-eightieth of an inch. 



EXPLANATION OF PLATE XVII. 



Fig. 1. — SijncJueta tavina^ side view. 

 ,, 2. — The same, dorsal view. 

 ,, 3. — Jaws of Synchceta tavina. 



