125 



beneath the body. The apex of the flagellum reaches nearly to the 

 posterior extremity of the cephalothorax when in this folded condition. 

 The total length of the inferior pair is one-third greater than the supe- 

 rior pair. 



The other parts that were mutilated in Dana's specimen were the pos- 

 terior stylets. A description of these will therefore complete the account 

 of the entire animal. 



The outer caudal lamella are longer than the inner ; both are lanceo- 

 late in shape, and serrated along their edges. The two stylets termi- 

 nating the caudal segment are linear, and of the same length as the outer 

 caudal lamellae. Two short stylets articulate with the outer edge of the 

 first just above the middle, and reach exactly half way to the terminal 

 point. The fifth and sixth abdominal segments are much narrower 

 than the preceding, and are apparently consolidated. 



HYPEEID^. 



HYPERIN^. 

 LESTRIGONUS RUBESCENS, Dana. 



Lestrigonus rubescens, Dana, U. S. Expl. Exped. Crust., ii, 984, pi. 67, f. 9. — Sp. Bate, 

 Cat. Amphi. Crust., 290, pi. xlviii, f. 5. 



Locality: North Pacific Ocean. Latitude 1° north j longitude 122^ 

 west. Collected May 7, 1873. 



My reasons for retaining the genus Lestrigonus will be given under 

 Hyperia tricuspidata. 



HYPERIA TRICtJSPIDATA, n. sp. 

 Head large, deeper than broad, irregularly quadrangular from a lateral 

 view, excavated in front. Eyes large, occupying most of the lateral 

 portion of the head. Superior antennae shorter than the head, stout; 

 base short, four-jointed ; first joint longest, distal end enlarged ; the 

 second, third, and fourth short, together shorter than the first ; flagellum 

 broader than the peduncle, oval, acute at the apex, about three times 

 as long as the base, uniarticulate ; a few long auditory cilia at apex; a 

 single row of short hairs on the inferior surface. Inferior antennae rise 

 from the inferior portion of the head, near the buccal region ; more than 

 twice as long as the superior pair ; peduncle four-jointed ; first and sec- 

 ond joints long; first about half the length of the second, extending to 

 the anterior margin of the head, but not exposed beyond It; second joint 



