74 DR. N. ANNANDALE 



"Investigator," whose collection of Cirripedia Pedunculata I hope to describe shortly; 

 but it is very possible that all of them exist in the Indian seas. Their localities and the 

 names given them are as follows : — 



I. 



Scalpellum inerme 



.. Bali Straits 



: 160 



2. 



„ sociabih 



, . . ,, 



?> 



3- 



Alepas malaysiana 



Gaspar Straits 



: 30 



4- 



„ gig™ 



... Bali Straits 



: 160 



Of the tour species, it will be seen that two belong to the genus Scalpellum, which 

 occurs in all seas and has a range in depth from about twenty to at least two thousand 

 fathoms. The other two represent the genus Alepas — a much smaller genus confined to 

 warm and temperate regions and occurring both on the surface attached to floating 

 objects and at considerable, but not, so far as is known, at great depths. 



Scalpellum inerme is represented by a single female specimen, which was probably 

 adult but did not happen to be breeding when captured. It appears to be the largest 

 Stalked Barnacle as yet described, and cannot be confused with any other known species, 

 the enormous development of the membranous part of the capitulum, the relatively small 

 size but compact structure of the calcified plates of the same region, the regular and 

 complete armature and considerable length of its peduncle, distinguishing it, combined 

 with its bulk, from all other Scalpella. In the case of the type specimen, the whole 

 of the capitulum and part of the stalk were concealed beneath an incrusting Alcyonarian ; but 

 the connection between the two organisms was probably fortuitous, as the same Alcyon- 

 arian had also overgrown the valves of one of the largest specimens of 6*. sociabile, despite 

 the hairiness of its membrane. (No degeneration of the calcified plates had taken place in 

 the case of the latter specimen as a result of its occlusion.) 



Of 6". sociabile we have a large number of hermaphrodite individuals of different ages and 

 belonging to two distinct assemblages, the larger of which was ultimately attached to the 

 peduncle of S. inerme, the smaller to that of Alepas gigas. In each case the young of one 

 individual or of its neighbours have settled upon its capitulum and peduncle, and have in 

 their turn been similarly obsessed ; so that what may almost be called a branching colony 

 has arisen, though of course there is no organic connection between the individuals which 

 compose it. The capitula of those individuals which are not covered with the Alcyonarian 

 support a plentiful growth of a small Hydrozoon. 



The affinities of 6*. sociabile would seem to be with «S. molucccanum, Hcek, and *S. molle, 

 Aur. ; but without examining specimens of all the species in question it is difficult 

 to pronounce a definite opinion on this point. In any case, the new form appears to be 

 worthy of true specific rank. 



Alepas gigas apparently reaches a larger size than any species of its genus hitherto 

 described ; while the scattered hairs on the surface of its integument appear to be 

 unique as far as Alepas is concerned. Unfortunately only one specimen was taken. It is 

 probably adult, but bears no eggs. The opaque integument of this and the succeeding 

 form is characteristic of species attached to the bottom, those which adhere to floating 

 objects being frequently (as in the case of A. indica) quite transparent. 



