320 DESCRIPTIONS OF PARASITIC COPEPODA. 



described in this paper, by the shape of the auterior antenuse and of the 

 thoracic appendages. By contraction the head often becomes nearly cir- 

 cular in dorsal view, with the anterolateral corners extended forward 

 beyond the median anterior margin, and with the thorax immediately 

 following the hood-like dorsal expansion. In such cases, the thorax is 

 also very short. 



The average length of the body, in lemales, is about G or 7""". The 

 color of living specimens is whitish, tbe head and most of the thorax 

 with its appendages being translucent ; remainder of the body mostly 

 opaque; ovigerous tubes slightly yellowish. In alcohol the body be- 

 comes yellowish-white and the ovigerous tubes much darker. Just be- 

 fore hatching, the latter become pinkish, due to tbe color of the embryos 

 in the eggs. 



This species is of very frequent occurrence iu the mouth of the com- 

 mon flounder, ParaUchthys dentatvs (L.) Jord. & Gilb., at Wood's Holl, 

 Mass., and vicinity, many specimens having been collected by the U. 

 S. Fish Commission in 1883 (603(5, G037, 6049, 6077, 6082). . It generally 

 attaches itself in the front part of the mouth, holding on tightly by 

 means of its hooked antennie, its head often partly buried in the soft 

 skin. Males are often found attached to the females, and a side view of 

 a male is represented on plate VIII, fig. 7. 



ChondracanthuH (jaleritus appears to correspond more nearly, in its 

 general shape and characters, with Chondr acanthus cornutus of Europe, 

 than with any other described species. I have not been able to examine 

 specimens of the latter species, but a comparison with published figures 

 indicates that the anterior antenna) and mouth parts, at least, furnish 

 good distinguishing characters. 



Chondracanthus phycidis, sp. uov. 



(Plate IX, figs. 1-6; plate X, figs. 8-13.) ' 



This species is of about the same length as Chondracanthus galeritus, 

 but generally rather stouter, when most extended about twice as long 

 as broad, when much contracted in alcohol fully two-thirds as broad as 

 long; ovigerous tubes large, straight, or slightly curved, usually about 

 three-fourths as long as the body, but sometimes of about the same 

 length. 



Head large, about one-third the length of the entire body, broadly 

 suboval in outline, as viewed from above, the greatest width being 

 nearly equal to or even slightly exceeding the length. It is more or 

 less abruptly narrowed toward the front, generally more so than in the 

 figure given, with the anterior margin straight or slightly convex in 

 the middle. The lateral margins diverge rapidly from the front, and 

 are at first slightly concave, but soon round outwardly, the posterior 

 two-thirds of the head in length being quite broad and with strongly 

 convex sides. In side view the dorsal contour is strongly arched, the 



