532 REPORT ON ZOOLOGY, MDCCCXLIV. 



whether Rataria may not be a young condition of Velella ; 

 in the explanation also of the various organs of these 

 Acalephs he differs from the hitherto received notions re- 

 specting their organization. 



Dujardin (Comptes rendus, t. xvi, 1843, p. 1132; or 

 Annales d. Sc. nat., t. xx, 1843, p. 370) has observed 

 minute Zoophytes allied to the Syncorynse, from the Medi- 

 terranean, and has described them under the name of 

 Stauridium. These animals constituted clavate expansions 

 at the extremity of a branched, horny stem, and presenting 

 four arms disposed in the form of a cross. The arms, a 

 millimeter in length, terminated with a small enlargement, 

 containing, as in the Hydra, spinigerous vesicles. Similar 

 vesicles also occurred in the stem. These Stauridia seized 

 Entomostraca (Cyclops) and swallowed them, for which pur- 

 pose they widely opened the mouth, which is placed in the 

 centre of the tentacles. This organ was furnished with 

 several short rudimentary tentacles, which were without the 

 spinigerous vesicles. In the interior of the branches of the 

 polypidom was a canal clothed with vibratile cilia. Dujardin 

 believed that the Stauridia constantly multiply themselves by 

 gemmation, at all events he observed them in that condition 

 during two years without Medusse being produced from 

 them. But when much nutriment was present in the 

 water, he remarked at the bases of isolated Stauridia two 

 or three red buds pullulate, which finally assumed in all 

 respects the form of the female Syncoryne sarsii. The 

 campanulate transparent disc of this progeny was furnished 

 with eight to ten marginal tentacles ; at the base of each of 

 these tentacles was a slight swelling with a black eye-speck ; 

 at the bottom of the bell rose a reddish stomach, whilst 

 from the border a contractile membrane was extended over 

 its mouth, in the centre of which membrane was situated 

 the oral orifice. The tentacles of these young medusiform 

 creatures 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, 



