The Genus Synchceta. Btj C. F. Roussclct. 401 



The eye is large, red, usually cleft in two halves, and seated on 

 the rounded brain mass. 



The mouth is shield-shaped and guarded all round by a single 

 row of very small stiff converging hairs. The mastax is large, of the 

 usual Synchreta shape and type ; the fulcrum seems to be particu- 

 larly long ; the unci have each five pointed teeth. The thin-walled 

 oesophagus arises in the middle of the dorsal side of the mastax, is 

 fairly long and not ciliated in its interior. The stomach is thick- 

 walled, consisting of large rounded granular cells, and carrying the 

 usual gastric glands ; the intestine is not very well marked off. 

 The lateral canals appear to be attached to the walls of the stomach 

 and reach forward as far as the gastric glands only. According to 

 Dr. Levander each canal forms here a convoluted knot from which 

 two branches are sent off. One branch goes forward a short distance 

 in the body-cavity, is held in position by a fine thread fixed to the 

 body-wall, and ends in a single flame-cell. The contractile vesicle 

 is large, situated at the base of the foot on the ventral side ; the 

 lateral canals make several turns in its walls before opening into it. 



The ovary is oval, of usual structure, and lies across the body- 

 cavity on the ventral side. Two foot-glands are very prominent 

 in the stout foot. 



The eggs are slightly oval in shape and generally carried about. 

 I found several eggs still attached to the toes by a fine thread in 

 the preserved specimens ; their size is 109 /j, (233 in.) long by 88 fx 



<2 8 9 in -) broad - 



As far as is at present known S. baltica is found only in the 



Baltic, where it is truly pelagic, occurring in great abundance in 



the open sea as well as in all the»large and small bays. It is well 



known that the salinity of the water of the Baltic is much less than 



that of the North Sea, due to its enclosed position, to the absence 



of tides, and to the great volume of fresh w T ater that is constantly 



poured into it by numerous rivers. 



According to Dr. Levander the greatest total length of S. baltica 

 is 523 /j. (^ in.) The largest preserved specimen I have received 

 measured 455 /x (^ in.) long by 245 fi (y^j in.) wide at the auricles. 



The male has not yet been observed. 



Synchaeta gyrina Hood. 

 PL VIII. fig. 17. 



BIBLIOGRAPHY. 



Hood, John. — Chats about Eotifers: Synchceta gyrina. Science Gossip, 1887, 



p. 149, 2 figs. 

 Hudson & Gosse— The Eotifera. Supplement. London, 1889, p. 18. 



Spec. Char. — Body large, barrel-shaped, not much wider in 

 front, and tapering gradually posteriorly to the short foot and 

 toes ; eye cervical, appearing double ; auricles comparatively 



