Papers from Dr. Th. Mortensen's Pacific Expedition 
1914—16. 
IL 
On a gall-producing parasitic Copepod, 
infesting an Ophiurid. 
B 
Dr. Th. Mortensen gr K. Stephensen. 
In a dredging from a depth of about 600 meters, 7 miles S. 
of Olutanga, Mindanao, March 8th 1914, I found a singular little 
white Ophiurid, attached to a white Stylasterid. It caught my at- 
tention, especially on account of a marked gall-like swelling at the 
base of one of its arms. On examining it more closely after my re- 
turn from the voyage I found that the swelling really was a gall, 
which contained a remarkable parasitic Crustacean. My friend, Mr. 
K. Stephensen, to whom I showed it, found it to be a Copepod 
of an interesting new type. No other instances of gall-producing 
Copepods being known in Ophiurans,!) and as, furthermore, the 
Ophiurid proved to be an interesting new species of the genus Astro- 
Charis, of the family Trichasteridæ, we have thought it worth 
While giving, in a joint paper, the description of the Ophiurid and 
Its parasite, 
men eeNEN 
i Gall-producing Copepods are known from the Echinoids, viz. Pionodes- 
modes phormosomæ in Hygrosoma Petersi (A. Ag.) (R. Koehler. Échi- 
nides et Ophiures des campagnes du Yacht W"Hirondelle. Résultats des 
Camp. scientifiques. Monaco. Fasc. XII. 1898, Pl. X), and Echinocheres 
£lobosus in the spines of Calveria gracilis (H. J. Hansen. Echinocheres 
Slobosus n. g., n. sp., a Copepod parasitic in the spines of an Echino- 
thurid. Vid. Medd. Nat. Foren. København. 1902. p. 437 Pl. XV). 
