426 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 9» 



SUMMARY 



The genus Paranthessius Claus, 1889, is reviewed and redefined to 

 include species formerly assigned to Diogenidium Edwards, Ilerr- 

 mannella Canu, Lichomolgus Thorell (part), Pseudolichomolgus 

 Thompson, Pseudolichomolgus Pesta, and Pestalichomolgus Wilson. 

 A key to the 18 species is presented, with synonymies and a compilation 

 of the published distribution. 



Representatives of the genus have been found in semiparasitic or 

 commensal association with a number of common clams of the Pacific 

 coast. Paranthessius colutiibiae (Thompson) was taken from the 

 gaper clam, Schizothaerus nuttallii (Conrad), and from Protothaca 

 tenerrima (Carpenter). 



Kew species are Paranthessius panopeae^ from the geoduck, Panope 

 generosa Gould; P. tivelae from the pismo clam, Tivela stultorutn 

 (Mawe) ; and P. saxidomi and P. per plexus from the Washington 

 clam, Saxidomus nuttallii Conrad. 



LITERATURE CITED 

 Atkins, D. 



1934. Two parasites of the common cockle, Cardiiim edule, a rhabdocoele, 

 Paravortcx cardii, and a copepod, Paranthessius rostratus (Canu). 

 Journ. Mar. Biol. Assoc, vol. 19, pp. 669-676. 

 Beian, a. 



1924. Parasitologia Mauritanica. Mat^riaus pour la faune parasitologique 

 en Mauri tanie. Arthropoda (l""* Partie) Copepoda. Bull. Comit6 

 I^tudes Hist. Sci. Afrique Occidentale Franc, July-Sept, 1924, pp. 

 4-66, 67 figs. 

 Canu, E. 



1S91. Les copdpodes marins du Boulonnais. V. Les semiparasites. Bull. 



Sci. France et Belgique, vol. 23, pp. 467^87. 

 1891. Sur quelques copc^podes parasites observes dans le Boulonnais. 



Comptes Rendus Acad. Sci. Paris, vol. 113, pp. 43:1-437. 

 1802. Les cop6podes du Boulonnais. Morphologie, embryologie, taxonomie. 

 Trav. Lab. Zool. Maritime Wiraereux-Ambleteuse (Pas-de-Calais), 

 vol. 6, pp. 1-354, 30 pis. 

 1804. Note sur les cop6podes et les ostracodes marins recuellis par M. Henri 

 Gadeau de Kerville dans la region de Granville et aux iles Chausey 

 (Manche). Bull. Soc Amis Sci. Nat. Rouen, ser. 3, vol. 30, pp. 127- 

 138. 

 1804. Notes de biologic marine, faunistiques ou ^thiologiques. V. Observa- 

 tions sur quelques copt'podes parasites des moUusques comestibles 

 de la Manche. Ann. Sta. Bquicole Boulogne-sur-Mer, vol. 2, pt. 1, 

 pp. 1-2S, 4 pis. 



1898. Note sur les cop^podes et les ostracodes des cStes de Normandie. Bull. 



Soc Amis Sci. Nat. Rouen, ser. 4, vol. 33, pp. 380-i22, 8 pis. 



1899. Sur LicJiomolf/us trochi, nov. sp., cop^pode nouveau parasite d'un mol- 



lusque. Trav. Lab. Zool. Maritime Wimereux-Ambleteuse (Pas-de- 

 Calais), vol. 7, pp. 73-79, 1 pi. 



