532 REPORT ON ZOOLOGY, MDCCCXLIV.

whether Rataria may not be a young condition of Velella ;in the explanation also of the various organs of theseAcalephs he differs from the hitherto received notions re-specting their organization.

Dujardin (Comptes rendus, t. xvi, 1813, p. 1132; orAnnales d. Sc. nat., t. xx, 1843, p. 370) has observedminute Zoophytes allied to the Syncorynse, from the Medi-terranean, and has described them under the name ofStauridium. These animals constituted clavate expansions,at the extremity of a branched, horny stem, and presentingfour arms disposed in the form of a cross. The arms, amillimeter in length, terminated with a small enlargement,containing, as in the Hydra, spinigerous vesicles. Similarvesicles also occurred in the stem. These Stauridia seizedEntomostraca ( Cyclops) and swallowed them, for which pur-pose they widely opened the mouth, which is placed in thecentre of the tentacles. This organ was furnished withseveral short rudimentary tentacles, which were without thespinigerous vesicles. In the interior of the branches of thepolypidom was a canal clothed w r ith vibratile cilia. Dujardinbelieved that the Stauridia constantly multiply themselves bygemmation, at all events he observed them in that conditionduring two years without Medusae being produced fromthem. But when much nutriment was present in thewater, he remarked at the bases of isolated Stauridia twoor three red buds pullulate, which finally assumed in allrespects the form of the female Syncoryne sarsii. Thecampanulate transparent disc of this progeny was furnishedwith eight to ten marginal tentacles; at the base of each ofthese tentacles was a slight swelling with a black eye-speck ;at the bottom of the bell rose a reddish stomach, whilstfrom the border a contractile membrane was extended overits mouth, in the centre of which membrane was situatedthe oral orifice. The tentacles of these young medusiformcreatures were of a bifurcate form, so that the animals,when they had become detached from the parent polypidom,resembled in all respects the Eleutheria of Quatrefages.