8 ARKIV FÖR ZOOLOGI. BAND 14. N.O 10. 



backvvard nearly at right angles to the basal joint, the ter- 

 minal joint a simple curved spine. Each first maxilla is 

 armed with two plumose setae, one directed ventrally and 

 one laterally. The second maxillae are simple and nearly 

 straight, terminating in a single spine. In the maxillipeds 

 the terminal clavv is folded back against the basal joint and 

 there is a small accessory claw on the outer margin at the 

 base of the terminal claw. 



The first swimming legs have very wide rami which are 

 heavily armed with flattened plumose setae, but each ramus 

 is apparently one-jointed. The rami of the second, third 

 and fourth legs are three-jointed, with the arrangement of 

 spines and setae shown in the figures. The fifth legs are 

 two-jointed, the terminal joint with but a single spine. 



Color (preserved material) white, faintly tinged with 

 brown. 



Total length 3.2 o mm. Width of cephalothorax 1 mm. 

 Length of egg strings 1.9 o mm., width 0.3 6 mm. 



(coelus, sunken or pitted, alluding to the front of the 

 cephalothorax). 



Remarks. This species may be distinguished from the 

 three already described as follows. From carchariae by the 

 fact that the free segments of the thorax diminish regularly 

 in size; from flagellans by the shape of the cephalothorax 

 in dorsal view and by the fact that the cephalothorax is 

 inclined only 45 degrees to the body instead of being at 

 right angles to it; from alhidus by the comparative size of 

 the cephalothorax and the first three free thorax segments 

 and by the details of the swimming legs. 



It is also distinguished from them all by the deep pitting 

 of the front of the cephalothorax, which is something unique 

 in copepod anatomy. 



Choiulracantlius distortus New Species. Pl. 4, figs. 33 — 39. 



Höst and record of specimens. Two lots of this para- 

 site were obtained. The first contains förty female speci- 

 mens, nearly all with egg strings and each with one or more 

 attached males. They were taken from the gills of Zeus japo- 

 nicus captured May 13, 1914 in a depth of 110—115 fathoms 



