400 



opment takes place directly without any metamorphosis. The 

 gastrulas soon become less active and after a short time lose their cover- 

 ing of cilia. The subsequent changes until the assumption of the pen- 

 tacula form involve so many debatable points that they cannot be 

 entered into here but a complete account of them will be published 

 hereafter. The young remain in the body-cavity of the adult for an 

 indefinite period ; many are born when not more than five or six mm 

 long and with the tentacles still few and simple; but it is no uncommon 

 occurrence to find young 20 mm long, with branching tentacles and 

 pigmented skin, still inside the adult. The young escape from the 

 body cavity into the cloaca and thence through the anus to the exterior. 



Habits: The animals live more or less socially in clusters of sea- 

 weed on the roots of mangroves. They creep about by means of the 

 long, slender tentacles, assisted by the numerous anchors in the skin. 

 Theirfood consists of minute algae, crustaceans and worms. They are very 

 delicate, sensitive to changed conditions and do not thrive in aquaria. 



Distribution: I have found this Synapta, only at Port Royal 

 in Kingston harbor. I have looked for it elsewhere in the harbor and 

 in suitable places in other ports of Jamaica but without success. It 

 appears to be very local even at Port Royal and the area, where it may 

 be fovind at all commonly, is very limited. 



From all these facts, it is clear that, altho differing in its manner 

 of life, its being viviparous and its lack of a metamorphosis, from 

 other members of the genus, this species is a true Synapta. As Lud- 

 wig has already suggested (Arch, de Biol. Vol. II, 1881) there ought 

 to be some better ground for generic distinction than the stage at which 

 the young are born, and lacking this, Synaptula has no standing as a 

 genus and becomes a synonym of Sytiapta. The species vivipara be- 

 longs to the same section of the genus as S. inhaerens, as shown by 

 the anchors and plates and the number of tentacles. It is very interesting 

 to note that in every particular given in his description, the species 

 from Bermuda described by Théel (Challenger Report, Vol. XIV, 

 Part XXXIX, page 10) as S. pietà agrees with S. vivipara. As there 

 was only one small specimen of ^. piota in the collection and nothing 

 is known of its habits, the identity of the two species is uncertain but 

 at any rate, their similarity is very remarkable and further information 

 regarding the Bermuda species would be of great interest. 



A more general account oi S. vivipara with figures of the anchors 

 and plates and the early stages of the embryo may be found in the 

 «Journal of the Jamaica Institute« for July, 189G. 



Marine Laboratory of the Johns Hopkins University, Port Henderson, 

 Jamaica, June 30, 1896. 



L>rucK von Breitkopf ft Hfirtel in Leipzig. 



