AMERICAN MUSEUM NOVITATES 



Published by 

 Number 81 Thb American Museum op Natural History June 22, 1923 



New York City 



59.f>3,4P(72.2) 



A NEW GENUS AND SPECIES OF PARASITIC COPEPOD FROM 

 LOWER CALIFORNIA 1 



By Charles Branch Wilson 



In 1912 Gravier published as one of the scientific documents of the 

 second French Antarctic Expedition under Dr. Jean Charcot a paper 

 entitled 'Crustaces parasites d'annelides polychetes.' 2 In addition to 

 presenting new genera and species he gave a general discussion of many 

 forms previously described belonging to that heterogeneous group known 

 as the Ascidicolidse. He noted that this name is very poorly suited to 

 the parasites that compose the group, since it includes a large number 

 whose hosts are not ascidians, and he was equally opposed to the name 

 Annelidicolidte proposed by some authors for such copepods as are found 

 parasitic upon annelids. He stated very clearly that our present knowl- 

 edge of these annelid parasites is insufficient to enable us to group them 

 at all rationally. The males of many of them have never been seen 

 and we know nothing of the development stages of most of them. 



We may make a general distinction between those that live within 

 the digestive tube of their host and those that live upon the outside of the 

 host's body. But this difference in habitat ought not to separate related 

 genera, and Gravier located his new genus, Bactropus, an intestinal para- 

 site, in the same family with genera that live upon the outside of the 

 annelid's body. 



This family was first proposed by Giesbrecht in 1895, Mittheilungen 

 Zool. Station Neapel, XII, p. 225. After describing Seridium rugosum, 

 a new annelid parasite, he remarked that several of these copepods 

 agreed in having an elongated body and rather distinct segmentation. 

 For this reason he grouped them into a family which he named Clausiidae 

 from Clausia, the oldest of them. He included in the family Clausia 

 Claparede, 1863; Donusa Nordmann, 1864; Rhodinicola Levinsen, 1878; 

 and Seridium Giesbrecht, 1895. He mentioned also Sabellacheres M. 

 Sars, 1861, but said it had never been described with enough detail to be 

 certain of its systematic position. This statement was undoubtedly 



'Scientific Results of the Expedition to the Gulf of California in charge of C. H. Townsend, by 

 the U. S. Fisheries Steamer 'Albatross,' in 1911; Commander G. H. Burrage, U. S. N., command- 

 ing. XI. Published by permission of the U. S. Commissioner of Fisheries. 



2 'Deuxieme expedition antarctique francaise (1908-1910).' 



