276 Transactions of the Society. 



Synchsetse, which on the whole are much the same as in other 

 Rotifers, and moreover, would require a separate volume. My 

 intention rather has been to give a sufficiently detailed description 

 and good figure of each species, so as to clear up the existing un- 

 certainty and allow any one of the species to be readily identified. 

 I trust this has been accomplished in this memoir on which I have 

 been at work for some years * 



Synehaeta pectinata Ehrenberg. 



PI. III. fig. 1, and PI. IV. fig. 7. 



Synonymy. 

 Synchceta mordax Gosse. 

 Synchosta oblonga Gosse. 



BIBLIOGBAPHY. 



Ehbenbebg, G. F. — Abhandl. der Akad. d. Wissensch. zu Berlin, 1831^ 



p. 135; 1833, pp. 221, 335, pi. x. fig. 3. 



Die Infusionsthierchen. Leipzig, 1838, p. 437, pi. 53, fig. 4. 



Gosse, P. H.— Ann. and Mag. of Nat. Hist., 1851, p. 197. 



Leydig, F. — Ueber den Bau u. Systemat. Stellung der Kadertbiere. Zeitsch. 



f. w. Zool., Bd. vi. 1854, p. 41. 

 Hudson, C. T. — Synchaeta mordax. Mon. Micr. Journ., vol. iv. 1870, p. 26, 



pi. 56. prs . 



Hudson & Gosse.— The Botifera. London, 1886, vol. i. p. 125, pi. 13, fig. 3. 

 Webeb, E. F. — Faune Botatorienne du bassin du Leman. Bevue Suisse de 



Zool., Geneve, 1898, vol. v. p. 392, pi. 16, fig. 15. 



Spec. Char. — Body sub-conical, very broad and convex an- 

 teriorly ; auricles large, more or less pendent ; two small cylin- 

 drical fleshy prominences bearing a broad brush of setse on front 

 of head ; four frontal styles, the outer pair the largest ; eye round,, 

 dark red or bluish-purple in colour ; toes two, small, acute. Size 



EXPLANATION OF PLATE IV. 



Fig. 4.— Synehxta ttylata Wierz. 9 Dorsal view. X 350. 

 ,. 4a „ „ „ The egg. x 275. 



,, 5 „ longipes Gosse ? Dorsal view. X 400. 



6 „ kitina sp. n. Rouss. ? Dorsal view. X 500. 



„ pectinata Ehrbg. The jaws. X 275. 



» 7 \ 

 „ 7aJ 



* Dr. Wesenberg-Lund of Copenhagen, in a paper published in 1900 (Biologisches 

 Centralblatt, Bd. xx. Nos. 18 and 19, 1900), wished to recognise only two fresh- 

 water species of Synchj^ta, namely 8. pectinata and tremula, considering all the 

 other described species as merely seasonal varieties of these main forms. I am not 

 inclined to make or maintain new species out of mere variations of size or form, but 

 when these are accompanied by constant internal and external anatomical characters, 

 males aud eggs of different shape and structure I think it is going too far to fuse 

 them all into one or two species. The animal Dr. Wesenberg-Lund calls S. pectinata 

 minor is most probably S. ohlonga, which may occasionally be 6een carrying an egg 

 for a short time. 



