TWO NEW SPECIES OF COMMENSAL COPEPODS FROM 

 THE WOODS HOLE REGION 



By H. R. Seiwell 



Of the University of North Carolina 



During the summer of 1925 I discovered that the common sea pork, 

 Amaroucium, collected in the vicinit}^ of Woods Hole, Mass., con- 

 tained Harpactid copepods in its branchial chamber. 



A dozen pieces of Amaroucium, 4 to 5 inches in length, were col- 

 lected, and after being washed in fresh water and carefully wiped 

 were placed in a dish of strained sea water and cut in pieces. The 

 sea water was strained three times through No. 18 Miiller bolting 

 silk. The mesh of this bolting silk is sufficient to remove any cope- 

 pods which might be present. At the end of a few minutes the con- 

 tained copepods were carefully picked out of the dish with a small 

 pipette and killed in formalin. An examination revealed two species 

 of Harpactids, both of which were new to science and are described 

 in this paper. Both were in sufficient abundance to well establish 

 the species. Twelve specimens of Tisbe wilsoni, including a single 

 male, and 14 specimens of AmpMascus commensalis, including three 

 males, were collected. 



I wish to express my appreciation to Dr. C. B. Wilson for the 

 helpful assistance he gave me in the identification of these forms. 



Genus AMPHIASCUS G. O. Sars, 1905 



Generic characters. — Body slender, cylindrical in form with the an- 

 terior and posterior divisions not sharply marked from each other. 

 Cephalic segment of moderate size and not deep, rostrum well de- 

 fined and very mobile. Urosome with the genital segment in female 

 imperfectly divided in the center, and scarcely dilated in front; pos- 

 terior edge of all the caudal segments finely spinulose on the ventral 

 and lateral faces. Caudal rami generally short; apical setae slender. 

 Anterior antennae of usual structure, and, as a rule, composed of 

 eight articulations, four of which belong to the terminal part. Pos- 

 terior antennae with the terminal joint dilated distally and armed 

 outside with strong spines, at the tip with slender geniculate setae; 



No. 2739.-PROCEEDINGS U. S. NATIONAL MUSEUM, VOL. 73. ART. 18 



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