The Genus Synchceta. By C. F. Rousselet. 289 



The muscles, retractors of the head and foot, are normal, very 

 narrow and finely striated ; the transverse muscular bands, en- 

 circling the body under the integument, more particularly on the 

 dorsal side, are numerous, and more prominent than usual. 



In swimming this fine species is more vigorous and rapid than 

 S. pcctinata, bending and turning constantly; it is more pliable 

 also and flexible at the waist than any other species. When once 

 seen there is no difficulty in distinguishing it from S. pcctinata 

 even with a pocket lens. Its food seems to consist mainly of the 

 smaller rotifers, such as Polyarthra. 



The accompanying fine drawing (fig. 8) has been made by 

 Mr. Dixon-Nuttall from a living specimen I was able to send him. 



In size it reaches a total length of 505 fi (-^q in.) by 258 /x. 

 (r^g- in.) wide at the auricles ; the body a little below the auricles 

 is only 170 /j, (jiv ^ n -) wide. Dr. Zacharias gives the greatest 

 length as 600 /*. The male is as yet unknown. 



Synchssta stylata Wierzejski. 

 PL IV. fig. 4. 



BIBLIOGRAPHY. 



Wierzejski, Prof. Dr. A. — Rotatoria Galicyi, Krakau, 1892, p. 62, pi. iv. fig. 5. 



Spec. Char. — Body large, elongated, conical, tapering both 

 anteriorly and posteriorly ; foot long and styliform, carrying two 

 very small toes. Eye single, cervical, dark red. Egg spherical, 

 covered with very long and thin spines, floating in the water. 

 Habitat fresh-water lakes. Size, 242 /u, ( T ^ 5 in.) to 292 /j, (g J f in.). 

 Lacustrine. 



This well marked and fine species was first discovered by 

 Prof. A. Wierzejski in Galicia in 1892, and figured and described 

 by him in his Rotatoria Galicyi. I have met with it repeatedly, in 

 the summer months, in canals and lakes round London : Putney, 

 Hanwell, Willesden. The shape of the body is that of an elongated 

 cone, tapering gradually posteriorly to the foot, which is long, and 

 perfectly round and styliform, ending in two very minute, but 

 distinct toes. The head is elongated, and also tapers anteriorly to 

 a rounded point, which bears at its extreme front two bundles of 

 very fine, divergent, stiff setre. The auricles are of fair size. The 

 head carries the usual two pairs of styles ; the outer and larger pair 

 arise from well developed triangular fleshy flaps, and are continued 

 inward as far as the mastax. The mouth is situated on the ventral 

 side of the head, and on each side of it there is a bunch of three or 

 four long stiff setse, arising from a fleshy knob. The ciliary wreath 

 is situated on a ridge running round the head between the two pairs 



