Vlll 



(jorgia. We have giveu comparative tables of the species of Acantliogorfjia and 

 Acamptogorgia which show, at least, how quantitative many of the specific 

 distinctions are. One may safely predict that when type-specimens of all the 

 different species described are brought together and (-oinpared, some simplification 

 will be possible. The same is doubtless true in regard to the species of Acis and 

 Muricella ; and although we have been forced to name two new species, Acis 

 spinosa and Muricdla bengaknsis, subsequent study of some representatives in 

 the littoral collection has shown us that the spicules vary within such wide limits 

 even in the same colony, tliat these and other species must be regarded as simply 

 tentative. Among the Pennatulacea there are some particularly interesting 

 species, e.g. Protocaidon indicum, another member of the genus which has been 

 hitherto represented only by KoUiker's Protocaidon niolle ; Protoptilum medium, 

 which seems to occupy a jiosition intermediate between Protoptilum aberrans, 

 KoUiker, and Protoptilum carpentcri, Kcilliker ; Sclerohelemnon JcoUikeri, which 

 raises doubts as to the warrant for separating the two closely allied genera 

 Kophohelemnun and Sclerohelemnon ; Bathyptilum indicum, which comes near 

 Bathyptilum carpenteri ; Thesioides inermis, already referred to. 



The species of Umhellula raise the same difiiculties as those of Sympodium, 

 etc., — difficulties which we see no way of removing without a large number of 

 specimens. Again we find forms which differ from one another in their tout 

 ensemble of characters, though no one character by itself is very significant. 



In dealing with a specimen which agrees well with KoUiker's Leptoptilum, 

 gracile, we have accepted the conclusion of Grieg and Jungersen, that this is but 

 a young stage of the familiar Funiculina quadrangular is. It is a little remark- 

 able, however, that the large adult forms of this species should have escaped the 

 collectors. It may be that our Leptoptihim gracile is the young stage of another 

 species of Funiculina which we have called gracilis. 



Accepting Jungersen's arguments, we have described Microptilum willemoesii, 

 Kolliker, as Pavonaria tvillemoesii. 



In some ways the most beautiful specimens in a collection rich in fine forms 

 are the Pennatulids, — Pennatida indica, Pennatula veneris, Pennatula 

 splendens, and Pennatula pendula. 



Viviparity. 



In 1900, Professor S. J. Hickson announced his discovery of embryos in situ 

 in Gorgonia capensis, — the first case of viviparity that he had observed in his 

 wide and prolonged study of Alcyonarians. 



He pointed out, however, that viviparity had been previously reported, and 

 we quote his references : 



" Lacaze-Duthiers proved the precious coral to be viviparous, and according 

 to Marion and Kowalewsky the ' Clavulaires petricoles ' are viviparous, but the 



