ROTIFERA. 
577 
ROTIFERA 
BY 
E. Perceval Wright, M.A., M.D., F.L.S. 
Mecznikow, E. Ueber einige wenig bekannte niedere Tbier- 
formen. Zeitschrift fiir wissensch. Zoologie, Bd. xv. 
pp. 450-463, pi. 35; translated in Quart. Journ. Micr. 
Sci. Oct. 1866, pp. 241-248, pi. 5. 
. Apsilus lentiformis, eiii Radertbier. Zeitscbr. f. wis- 
senscb. Zoologie, Bd. xvi. pp. 346-356, Taf. 19 ; Sept. 1866. 
Clicdonotm and its allies.' Mecznikow (Zeitsclir. f. wiss. Zool. xv. 1865, 
p. 461) regards] all the forms described by Elirenberg as belonging to one 
species, C. larus ; the one described by M. Schultze as C. maxinius he calls 
C. schultzii, and another from the Marshes of Giessen C. hystrix. C. larus 
is figured pi. 35. fig. 6 , C. hystrix fig. 7, and C. tesselsatus fig. 8. Of the 
genus IchtJiydium he alludes to and figures a new species, I. ocellatum, from 
Charkow Q. c. p. 451, pi. 35. fig. 1). 
Chcctonotns larus. Mecznikow (/. c. p. 454) records the existence of winter 
as well as summer eggs in this species, and mentions facts proving that there 
is no metamorphosis in the Ichthydina. lie concludes that the nearest allies 
of this group are* the Rotatoria forming a small section which he calls Gas- 
trotricha, in contradistinction to the wheel-animalcula which he designates 
Cephalotricha (1. c. p. 458). 
Here may be noticed the remarks of Mecznikow (/. c. pp. 458-461, pi. 35. 
figs. 9-11) on JEchinoderes dtijardmii and E. monocerus, the systematic position 
of which is so very uncertain. The author says the genus bears no remark- 
able relationship to the Ichthydina, as M. Schultze bebeves, and still less to 
the Nematodes, as Ehlers maintains. Appended to these remarks is an account 
of Desmoscolex minutus. Clap., which is regarded as probably a larval con- 
dition of a known or unknown Arthropod {1. e. p. 461, pi. 35. fig. 12). 
Chcetura, g. n., Mecznikow (p. 452). Head somewhat broader than the 
rest of the body ; back with a series of elevations placed one after the 
other ; ventral surface covered with cilia ; a row of strongly bent bristles on 
the back of the tail end ; on the posterior extremity of the body are two very 
characteristic dichotomous furcal appendages. G, capricornia, sp. n. (p.452, 
pi. 36. figs. 2, 3), from Charkow. 
Cephodidium, g. n., Mecznikow (p. 452). Bottle-formed, with a broad, 
blunted head, provided with a distinct mouth, covered all over with long, 
vibratile hairs ; neck thin where joined to body, having on its dorsal surface 
very long and strong bristles, and on its ventral small vibrating hairs ; no 
1866. [voL. III.] 2 p 
