12 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.59. 



The first antennae are peculiar in the enlargement of the basal 

 joint into a wide hand with seven divisions or fingers each tipped 

 with a long and stout seta. The remainder of the antenna is at- 

 tached like a thumb on the outer margin of the hand instead of the 

 inner. It is not as long as the finger setae and is indistinctly three 

 jointed, each joint armed with short spines. The second antennae 

 are slender, cylindrical, and three jointed, the basal joint very short, 

 the other two much longer and about equal. The terminal joint car- 

 ries a short claw-like spine at its tip and three small setae on its outer 

 margin. 



Since there is but the single specimen it has not been considered 

 advisable to dissect out the mouth parts; but a profile view shows 

 distinctly a short and rather blunt mouth tube, with two pairs of 

 jointed maxillae, tipped with spines. The maxillipeds are large 

 and strong, three jointed; the terminal joint armed with a powerful 

 claw as long as the joint itself and but slightly curved. 



There are four pairs of biramose swimming legs, crowded closely 

 together. The rami of the first three pairs are three-jointed, but the 

 endopod of the fourth pair has only two joints. 



Color (preserved material), a uniform brownish yellow. 



Total length, 4 mm. Inflated cephalothorax, 2.20 mm. long, 2.25 

 mm. wide, 2.35 mm. thick. Length of egg strings, 2.40 mm.; 

 width, 1 mm. 



, Remarks. — It is to be regretted that there is but a single specimen 

 of this remarkable copepod. It presents, however, even in a cursory 

 examination so many points of divergence from other genera as to 

 leave no doubt of its validity. 



The inflated thorax suggests relationship to Notodelphys and 

 Doropygus, but the external egg cases offer an effective barrier 

 against even including it in the same family with those genera. 

 The enlarged basal joint of the first antenna finds a counterpart in 

 the genus Bomolochus, but is unknown amongst the semiparasites. 

 The maxillipeds are fully as well developed as in any of the fish 

 parasites and must function as powerful organs of prehension. 



So far as known no other copepod possesses anything that corre- 

 sponds to the curved horns found at the posterior corners of the 

 inflated cephalothorax. They are very different in structure and 

 hence probably in function from the processes found in the Chon- 

 dracanthidae and some of the Lernaeopodidae. Their only counter- 

 part seems to be the horns developed on the cephalothorax of the 

 Lernaeidae, but they can not be intended for the same purpose, since 

 they are not buried in the tissues of the host. And, finally, the anal 

 laminae are peculiar in being naked, laterally flattened and dorsally 

 curved, as in some of the Lernaeopodidae. 



