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Proceedings of the Eoycd Society 
numerous dredgings, both public and private, off the French and 
British coasts between the parallels of 40° and 57°. One would 
certainly have expected its appearance during the first cruise of the 
“ Porcupine ” in the neighbourhood of the 100-fathom line on the 
west of Ireland ; but no traces of it were met with. It was very 
abundant off the Tunis coast, both on tlie Skerki Bank and in the 
Bay of Benzert, specimens of all ages coming up on the tangles in 
great numbers, though unfortunately in a very much mutilated 
condition. These were noticed by Sir Wyville Thomson in the 
following passage : * — Many examples of the form known to 
Continental naturalists under the name of A. mediterraneus, Lam. 
sp., were dredged in the Mediterranean off the coast of Africa. I 
do not feel satisfied that this is identical with Antedon rosaceus 
of the coast of Britain, though the two specific names are usually 
regarded as synonyms. There is a great difference between them in 
habit, a difference which it is difficult to define.” It is curious that 
the extreme length of the dorsal cirri of these individuals did not 
lead Sir Wyville to identify them with Ant. ylicdangiwn {celtica^ 
Barrett), of which this is one of the special marks, as he himself 
points out. But I am strongly inclined to believe that he is right 
in differentiating the common Mediterranean type from the British 
Ant. rosacea. As pointed out above, however, the ‘‘Porcupine” 
only got a very few young specimens of it on the African coast. 
It is singular that while no parasitic M yzostoma occurred among 
the numbers of Ant. phala7igium dredged on the Tunis coast, some of 
the individuals obtained in the Minch in 1869, and at Station 13 
in 1870 (off Mondego) proved to be the hosts of a new species, 
AI. cdatum, which is briefly described by Professor von Graff 
further on. A single example of another new species, M. pidvinar, 
was also found attached to the peristome of one of the Minch 
specimens of Ant. phalangium, which does not appear to serve as 
host to the same species of M yzostoma as occur on Ant. rosacea. 
7. Antedon dentata, Say, sp. 
Antedon Sarsii.^ auct. 
H.M.S. “Porcupine,” 1869. Station 51. Lat. 60° 6' K long., 
8* 14' W. 440 fathoms. Temp. 42° F. One specimen. 
* Pi'oc, Roy, Soc. Edin,, vol, vii. p. 765. 
