78 PROCEEDINGS OF TPIE NATIONAL MUSEUM. vol.60 



but one or two are terminal and all the rest are on the posterior 

 margin, next to the carapace. The second antennae are developed 

 into powerful prehensile organs; their basal joints are long, much 

 swollen, and filled with strong muscles, which are supported by 

 several chitin bands and processes. 



The terminal claw is strongly curved and sharply pointed, with a 

 small and sharp spine near the base. 



The rostrum is short and stout, with the upper lip obtusely rounded 

 and the lower one more acute. The first maxillae are relatively large 

 and three-jointed, the joints subequal in length. The two basal joints 

 are moderately stout, the terminal one is slender and bifid at the tip. 

 with the inner, ramus longer than the outer. The second maxillae 

 are made up of a rather stout basal joint, a narrower second joint of 

 about the same length, and a spine-like terminal claw. The distal 

 end of the second joint is armed with closely placed, acute, and more 

 or less curved spines arranged in several rows, mostly along the outer 

 margin. 



The maxillipeds are composed of a very large and stout basal joint 

 and a strongly curved terminal claw. The tip of this claw, and also 

 the one on the second antenna, is of a dark red amber color. On the 

 inner margin of the claw near the center is a smaller secondary claw 

 or tooth, and proximal to this the claw is at least partly divided by 

 a joint. 



The first swimming legs consist of a single flattened lamina, with a 

 tiny spine at its tip. They are so close to the maxillipeds that they 

 are largely concealed beneath the basal joints of the latter, with only 

 their tips visible. The second legs are biramose, the basal joint broad 

 and stout, the rami short, stout, and one-jointed. The outer margin 

 of the basal joint carries a long jointed seta ; the exopod is larger than 

 the endopod and is terminated by four stout spines, the outer of 

 which is the largest. The endopod has three similar spines at the 

 outer end and a fringe of fine hairs along the inner margin. The 

 third legs consist of a single lamina, like the first legs but smaller, 

 which is armed with three spines near its tip. 



Color. — The living male is bright red from the presence of blood 

 like the female ; preserved material is light cartilage yellow, the tips 

 of the claws of the second antennae and maxillipeds and the chitin 

 framework of the appendages a dark amber red. 



Total length, 4 mm. Cephalothorax 1,20 mm, long, 1.10 mm. wide. 

 Body 0.80 mm. wide. Fourth legs 1.50 mm. long. 



Remarks. — The fish were brought in alive by the Grmnpus and the 

 parasites were taken from them by Mr. Richard Rathbun and studied 

 while still living. He made detailed notes on their appearance and 

 structure, and Mr, J, H, Blake made drawings of both a male and a 



