NO. 2oa.^. A^ORTH AMERICAN PARASITIC COPEPODS—WIISON. 689 



Trunk, 9 mm. long, 1.50 mm. wide near the center. 



(elongata, elongate in its general proportions.) 



Remarlcs. — This species is apparently quite rare, but we must 

 remember that very few of the fish which serve as its host have ever 

 been exammed for parasites. It can be at once distinguished from 

 other species by the narrow and elongate cephalothorax and trunk. 



CLAVELLODES, nev/ genus. 



Generic characters of female. — Parasites of medium size (8 mm.); 

 cephalothorax distinctly separated from and much larger than the 

 trunk, and reflexed against the dorsal surface of the latter; head 

 somewhat enlarged and separated from the neck by a well-defined 

 groove; trunk plump, of varying length, without an abdomen, anal 

 laminae or posterior processes. First antennae slender, three- 

 jointed; second antennae biramose, destitute of claws; first maxillae 

 tripartite, the palp with a single seta; second maxillae so 'short that 

 the bulla is vktually on the trunk ; terminal claw of maxillipeds rein- 

 forced near the tip by an accessory claw, behind which the margin is 

 toothed for a distance. 



Generic characters of male. — Of medium size (1 mm.); body folded 

 upon itself so that the anterior and posterior portions are parallel, 

 while the central portion is at right angles to them, the whole com- 

 pletely fused without any distinction of parts or segmentation; gen- 

 eral form ellipsoidal, with the anterior margin almost squarely trun- 

 cated; mouthparts and genital process crowded together along this 

 margin; no anal laminae. 



First antennae indistinctly four-jointed; second antennae bira- 

 mose, endopod simple, exopod two-jointed; first maxillae similar to 

 those of the female; second maxillae larger and more powerful than 

 the maxillipeds, and pushed so far forward as to be even with, or in 

 front of, the anterior margin of the head. 



Type. — Clavellodes rugosa (Anchorella rugosa Kr0yer). 



(Clavellodes , Clavella and icdog, hkeness or appearance.) 



Remarlcs. — This new genus is estabhshed to include thi-ee species 

 which have hitherto been referred to Clavella. They differ so much, 

 however, from that genus in the structure of the second antennae, 

 first maxillae and maxillipeds of the female, and in the general form 

 and appendages of the male, that a new genus must be created to 

 receive them. The internal structure of the male, as described and 

 figured under the species rugosa (see p. 691), is pecuHarly interesting, 

 not only because it shows a marked difference from Clavella, but also 

 on account of the structure and arrangement of the entire sexual 

 apparatus. In the female of this new genus the head is widened by 

 the formation of prominent lateral lobes, the second antennae are 

 biramose, and the first maxillae are tripartite. In the male the body 

 34843°— Proc.N.M.vol.47— 14 44 



