460 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxv. 



ing the anal laminae. They scarcely project from the surface and 

 can be easily overlooked. Neither of the females obtained carried 

 egg strings, and so nothing is known of them. 



The first antennae consist of a one-jointed papilla on either side of 

 the mouth tube, a mere stump, apparently immovable. The second 

 pair are three- jointed, stout, and terminate in a small curved claw; 

 they are movable and evidently assist in prehension, particularly that 

 part which is concerned with the burying of the head when the para- 

 site first becomes fixed. The mouth tube is made up of the project- 

 ing upper and under lips; these are united at the base, but are sepa- 

 rate for their terminal halves. The upper lip is semicylindrical and 

 somewhat like a proboscis, while the under one is tongue-shaped and 

 just covers the semicy Under, making thus when closed a tube through 

 which nourishment can be conveyed. The mandibles and maxillae 

 are reduced to mere finger-like processes, the former in the space be- 

 tween the two lips, the latter on either side of the lower lip. 



There are no first maxillipeds ; the second pair are two- jointed and 

 well developed. They consist of a large swollen basal joint and a 

 small terminal claw which closes down firmly against it. They are 

 thus much better developed and more formidable organs of prehen- 

 sion than are common in this family of parasites. In most of the 

 genera possessing a swollen cephalothorax and a long buried neck, 

 these alone seem to attach the parasite securely to its host, and all 

 the organs that serve for prehension in other forms are rudimentary 

 or usually lacking. Here for some reason the second maxillipeds 

 have retained fully their normal size. 



There is but a single pair of swimming legs, one-jointed and very 

 rudimentary, attached to the cephalothorax close behind the maxil- 

 lipeds. The ovaries are in the form of oblong masses, one on either 

 side of the digestive canal in the genital segment. 



Total length, 38 mm. Length of head, 2.8 mm. ; of neck, 22 mm. ; 

 of genital segment, 7 mm.; of posterior processes, 7 mm. Width of 

 head, 2.2 mm. ; of genital segment. 2.5 mm. ; of neck, 0.7 mm. 



Color. — Of preserved specimens snow white throughout except the 

 mouth tube, mouth parts, and second antenna 1 , which are tinged 

 with red. 



( ( .rilis. slender.) 



The presence of a mouth tube, however imperfectly formed, places 

 this genus in the family Lernaeidae, but the male must be obtained 

 and examined before this point can be finally settled. The author 

 has taken a similar genus (as yet undescribed) from sharks along the 

 Atlantic coast. While in the female there was little evidence of a 

 mouth tube, in the male it was well developed and leaves no doubt as 

 to the location of the genus. The same will probably be found to be 

 true when the male of the present genus is obtained. 



