COPEPODS OF THE WOODS HOLE REGION 505 



segment serrate; maxillipeds long and slender, 2-segmented, with a 

 stout apical claw. Total length, 0.5-0.55 ram. 



Remarks. — The one lot secured by Rathbun are the only specimens 

 of this species thus far obtained. The size and shape of the head 

 and trunk and the stoutness of the posterior processes are the dis- 

 tinguishing characters. 



ACANTHOCHONDRIA GALERITA (Rathbun) 



FiGUitE 299, & 



Chrondracanthus galeritus Rathbun, Proc. U. S. Nat. Mus., vol. 9, p. 317. pi. 8, 

 figs. 1-7, pi. 10, figs. 1-7, 1SS6. 



Occurrence. — Many females with attached males were taken from 

 the mouth of the common flounder {Po.ralichthys dentatm), at 

 Woods Hole in August, 1883, by Rathbun, and in August, 1900, and 

 July, 1904, by Vinal Edwards. 



Distribution. — Not found outside the present area. 



Color. — Body whitish, the head and anterior thorax translucent, 

 the remainder of the body opaque; oviducts and ovisacs yellowish, 

 the latter becoming pink as they mature. 



Female. — Head a little longer than wide, widest anteriorly and 

 narrowed posteriorly, the carapace strongly arched and gibbous be- 

 hind; first segment much narrower than the head, second segment 

 the same width as the head, third segment considerably wider and 

 separated from the fourth segment; posterior processes short, stout, 

 and bluntly rounded. Genital segment as wide as long; the single 

 abdominal segment less than half the size of the genital segment, 

 with a pair of small setose caudal rami on the ventral surface near 

 the base. First antennae fleshy, triangular, and unsegmented; sec- 

 ond antennae stout; mandible long and acuminate, fringed with 

 coarse and rather blunt teeth; maxilla without a palp; each swim- 

 ming leg bifid at its tip, the branches acuminate. Total length, 

 6-7 mm. 



Male. — Body pyrif orm ; head fused with the first two segments and 

 much larger than the rest of the body; trunk 4-segmented; caudal' 

 rami stout, conical, and acuminate. First antenna cylindrical, 2-seg- 

 mented; second antenna rather larger and stouter than in the other 

 species ; maxillipeds also longer and stouter. Each swimming leg is 

 made up of a single dactylose segment tipped with two small setae. 

 Total length, 0.45-0.52 mm. 



Remarks. — This copepod is usually found in the mouth of the 

 flounder, just in,side the lips, with its head buried in the skin. It 

 can be identified by the obovate head, widest anteriorly, and the 

 short and blunt posterior processes turned downward beneath the 

 Qgg strings. 



