KO. 2280. THE Aii'U' COPEFOl) FAMILY ISFHYRIIDAE— WILSON. 589 



giving any reason for such action. Eichiardi in 1878 claimed it as a 

 new genus which he named Trypaphylum, but he added nothing to 

 Beneden's description. It was enumerated under this new name, with 

 a change in the spelling, by several subsequent authors, including 

 T. and A. Scott. In their excellent monograph on British Parasitic 

 Copepods Richiardi's genus was included and a brief diagnosis of 

 both sexes was given. From this account the present author has bor- 

 rowed very freely and acknowledges his deep indebtedness. Unfortu- 

 nately, no description has ever been given of the antennae and mouth 

 parts of the female, and in all the figures that have been published 

 the head of the female has been lacking. We are thus prevented from 

 locating the female exactly, but if the male, which was admirably 

 described and figured by the two Scotts, is of the same species it 

 shows beyond a doubt that the genus does not belong to the Ler- 

 naeidae. No Lernaean male lives long enough to appear with the 

 female on the final host, nor does it bear any resemblance to this 

 Trypaphylum iiiale. And the differences between this male and those 

 belonging to the Lernaeopodidae are just as great. 



On the other hand, there is a close similarity between the male 

 described by the Scotts and the two here given for the genus Rehe- 

 lula. Indeed, the only difference is the lack in the former of the 

 prominences at the back of the cephalothorax, containing the testes; 

 but this is more than offset by the elongation and complete fusion of 

 the basal joints of the second maxillae and maxillipeds. It is also 

 worthy of note that at the time the species was originally established 

 Beneden called attention to its close affinity with the genus Sphyrion^ 

 and several other authors have commented on this same relation. 

 Accordingly, in so far as we are acquainted with the details of the 

 structure of the two sexes, the genus Trypaphyhim. belongs with the 

 other genera in the Sphyriidae. Only one species has ever been 

 described, so that the genus is monotypic, but the specific name must 

 be credited to Beneden and not to Richiardi. 



Genus OPIMIA Wilson. 



Opimia Wilson. Pn»c. U. S. Nat. Museum, vol. 3.5. 1908, p. 459. 



Xxeneric characters of female. — General form elongate and slender,, 

 without any traces of segmentation; cephalothorax swollen into a 

 globe or sphere, smooth and without processes or horns. Neck cylin- 

 drical, of the same diameter throughout and two-thirds of the entire 

 length. Trunk narrow, longer than wide, with a single pair of pos- 

 terior processes, which are smooth, straight, and cylindrical; abdo- 

 men short and rudimentary. 



First antennae one-jointed papillae; second pair stout, uniramose, 

 and uncinate; mouth tube terminal, protruding; one pair of maxillae; 



