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REPORT ON ZOOLOGY, MDCCCXI.IV.
sum ; tentacula et oculi nulli. In this genus Rathke hasdescribed the three species, Amm. aulogaster, limacina, andcestroides, but afterwards found (Archiv, 1844, Bd. i, p.259) that the latter species coincided with Ophelia mamillataOerst. To the genus Siphonostoma he has added four newspecies : S. plumosum : corpore attenuato; cute verrucosa;superioribus setarum fasciculis inferiores longitudine multosuperantibus; cirris octo cylindraceis rnagnis; tentaculispaulo latioribus. S. vaginiferum : corpore attenuato; cutesubrugosa; setarum fasciculis cute tanquam vagina abductis ;cirris numerosis, parvis, in duos fasciculos collatis; tenta-culis multo latioribus et longioribus. S. villosum : corporebreviori; cute ubique villosa; setis inferioribus crassis,brevibus, superioribus multo tenuioribus et longioribus;cirris numerosis, parvis, in duos fasciculos digestis; ten-taculis multo latioribus. S. inhabile: corpore toroso dolii-formi; cute verrucosa; cirris 6 (8 ?) parvis; tentaculis paulolatioribus. Lastly, Rathke has instituted as a new genus,between Sabella and Clymene, that of Clymeneis, with thespecies. Cl. stigmosa, which differs from Sabella in the waneof bran chi a; on the head, and from Clymene in the narrowand slender posterior production of the body, which, conse-quently, is not furnished with any infundibuliform appendage.
According to the observations of H. Koch and Will(Archiv, 1844, Bd. i, p. 331) Chcetopterus pergamentaceusoccurs also in the Adriatic Sea. Peach (Institut. 1844,p. 419) thinks he has observed, that the Nereis tubicola isable to swim about on the surface of the sea; but this isdeclared by Porbes to be merely accidental.
A new and extremely remarkable Annelid, having theaspect of a young Syttis, has been discovered by Quatrefageson the coast of Brittany, and been named Dujardinia. (Comptesrendus, 1844, p. 77 ; or Ann. d. Sc. Nat. t. i, 1844, p. 19.)It has, on each side of the body, a row of motory organs,which recall in every respect the rowing organs of the Rota-toria ; its rudimentary feet, as in the other Branchiata,support stiff setae.