390 BALANID.E. 



cirrus is moderately short, with its segments rather broad 

 and protuberant, and thickly clothed with spines. The 

 third cirrus is of unusual length, being but little shorter 

 than the fourth pair ; its segments, however, are broad, 

 and are thickly clothed with spines, as are the two segments 

 of its pedicel : hence there is no real approach to that im- 

 portant character of the Chthamalinse, namely, the similarity 

 of the third with the three posterior pairs of cirri. The 

 numerous segments of the fourth, fifth, and sixth pairs of 

 cirri each support only two pairs of main spines ; between 

 each of these pairs there is a little tuft of fine intermediate 

 spines ; the upper of the two tufts on each segment is the 

 longest. In a specimen of C. patula, in which there were 

 fifteen segments in one ramus of the second cirrus, there 

 were fifty segments in either ramus of the sixth cirrus. At 

 the exterior bases of the pedicels of some of the anterior 

 cirri, there are large tufts of finely plumose, delicate hairs. 



Branchice. — These are of large size : they consist of a 

 isingle fold, much plicated and sub-plicated. 



Ovaria. — The ovarian tubes run into the parietes, and 

 fill up the interspaces between the radiating septa. 



liange, 8fc. — The three species seem to range together, 

 over the tropical and warmer temperate seas of the whole 

 world. C. patula and testudinaria are found in the Medi- 

 terranean, and the former at Charleston, in the United States ; 

 I have not heard of specimens from any point further 

 north. C. testudinaria and caretta live attached to turtles; 

 whilst C. patula always adheres to Crustacea, to large and 

 smooth gasteropod mollusca, and, I believe, sometimes to 

 ships' bottoms. I have not heard of the discovery of any 

 fossil species. 



Attachment. — Chelonobia patula leaves no impression on 

 the crabs and shells to which it is attached. I have seen 

 only a few specimens of C. testudinaria attached, and the 

 carapaces of the turtle were not at all, or scarcely at all, in- 

 dented by them. The case is very different with C. caretta, 

 in which the shell, even of young specimens, is always, as far 

 as I have seen, imbedded to some depth, and occasionally 

 to a very great depth in the tortoise-shell. From the extreme 

 hardness of the tortoise-shell, when drv, the imbednient 



