ISOPODA OE THE 'LIGHTNING' AND OTHEE EXPEDITIONS. 119 



The first gnathopods (iv. l*) have the basos with the rounded lobe, so usual in this 

 group, greatly developed ; the meros lies almost entirely on the inner side of the wrist ; 

 the wrist is large and bulky ; the hand united to the wrist by a thick neck, the rest of 

 the joint being broad and stout, with a short broad thumb, the inner margin of which 

 is minutely toothed, and at about one third of its length slopes down rather suddenly 

 to the little upturned nail ; there are two or three small teeth on the inner margin of 

 the finger, notably one near its root. 



The following six legs are slightly built, with long slender nails. In the first three 

 pairs the finger (iv. prp 1 ) exceeds the hand in length, and is minutely fringed or 

 pectinate, and rises from the midst of spines similarly ornamented. In the last three 

 pairs the finger (iv. prp s ) is not quite so long as the hand, and opposite to its concave 

 curvature there is, at the distal end of the hand, a short serrated slightly curved spine. 

 The short meros and the longer carpus have each a long incurved spine at the distal 

 end. 



The uropods (iv. pi.) consist of a short rather stout peduncle and a single conical 

 uniarticulate ramus, which is more than twice as long as the peduncle, and bears two 

 long setse at the blunted apex. 



There is no trace of pleopods on the first five segments of the pleon ; these segments 

 bulge out ventrally. 



Length 3 millim. 



The type and only specimen was dredged in 1869 by the ' Porcupine ' in 96 fathoms, 

 on the slope of the English Channel. (Station 35, lat. 49° 7' N., long. 10° 57' W.) 



Tribe II. FLABELLIFERA, G. O. Sars. 



Family ANTHURID^l. 



Animal greatly elongated, narrow, nearly cylindrical or depressed ; head much shorter 

 than following segment. Mouth-organs adapted for suction ; first gnathopods the 

 larger, subchelate ; second gnathopods and first pereeopods not very unlike in general 

 form to the first gnathopods, but more slender; remaining perseopods adapted for walking. 

 First pleopods large, expanded, and covering (generally in female) the remaining 

 pleopods. Telson linguiform ; uropods, outer branch one-jointed, and so articulated 

 as to arch more or less over the back of telson, inner branch two-jointed. 



This family consists of Isopods of remarkably elongated form, composed of segments 

 which are cylindrical or slightly depressed, those of the perseon (except, in some cases, 

 the last) being much longer than they are broad. The head is more or less quadrate, 

 shorter than the following segment, and having the eyes, when present, at the anterior 

 angles. The pleon sometimes has all the segments, except the telson, completely, at 



T 2 



