FEOM THE GULF OF GUINEA. 105 



extremely long, slender, jointed, setiferous sjiine, bearing a plumose seta at its extremity 

 (fig. 31). Length, exclusive of caudal spines, 2-4 mm. ; Icngtli to the extremity of the 

 caudal spines 12-5 mm. (J an inch). Anterior antennae (female) slender, about equal in 

 length to the first cephalothoracic segment, 6-jointed, sparingly setiferous, penultimate 

 joint very short. The upper distal end of the first joint is produced to form a broadly 

 conical tooth provided with an apical seta. A long " olfactory " appendage springs from 

 the end of the third joint. The relative lengths of the joints are nearly as follows : — 



10 ■ 12 ■ 13 . 8 . 1 . 3 

 1 2 3 4 5 6' 



Anterior antennse of the male very long aud slender, fully twice the length of tliose 



of the female, 7-jointed, penultimate joint extremely long ; the olfactory appendage that 



springs from the distal half of the fourth joint and the principal apical seta are also very 



long. The annexed formula shows the relative lengths of the joints : — 



12 . 13 . 5 . 15 . 6 . 38 ■ 12 

 1 2 3 4 5 6 7 ■ 



Both the male and female antenntB are geniculate between the first and second joints 

 (fig. 3i). Second and third joints of the posterior antennae elongate : secondary branch 

 very short, with two apical setae. Mandibles broad, with the truncate distal end 

 irregularly toothed and bearing a pectinate stout seta at the outer angle (fig. 36) ; no 

 trace of a palp was observed. The maxillae have a well-developed biting part aud a 

 small secondary appendage bearing three apical setae. Anterior foot-jaws small ; first 

 joint armed with two stout spines, setose on both edges, and a small spine and a seta ; 

 the very small terminal point bears three apical setae. The last three joints of the 

 second foot-jaws are very small and furnished with several long setae ; the inner distal 

 portion of the elongate second joint is produced and forms the base of a long, stout, 

 curved spine ; there is a small setiferous process on the inner margin of the proximal 

 end (fig. 39). The posterior foot-jaws in the male are somewhat similar to those of the 

 female, but smaller and less setiferous (fig. 40). The middle joint of the second, third, 

 and fourth pairs of swimming-feet shorter than the first or third ; the marginal spines 

 of the outer branches stout, dagger-shaped, and serrate on both margins ; terminal spines 

 elongate, falcate, serrate on the outer edge, the inner edge ciliate. Fifth pair of feet 

 simple, each foot armed with three long dagger-shaped spines on the outer margin and 

 two at the apex : both edges of these spines are serrate except near the base : there are 

 two plumose setae near the middle of the inner margin, and a plain seta near the base of 

 the outer margin of each foot, as shown in fig. 48. 



Hahitat. In a tow-net gatliering from 360 fathoms. Lat. 1° 65' 5" N., long. 5° 55' 5" E., 

 collected January 22nd ; and in tow-net gatherings from 185 fathoms and 235 fathoms, 

 Station 23, collected February 5th. 



Several specimens of this remarkable species were obtained. They do not agree with 

 ^gisthus aculeatus, Giesbrecht, — e. y. the fifth pan- of thoracic feet, &c. 



SECOND SERIES. — ZOOLOGY, VOL. VI. 14 



