300 DE. THOMAS SCOTT ON THE 



inner ramus of the first pair is considerably shorter than the outer one, and the end 

 joint is rather narrower than the first or second (fig. 5). 



Fifth pair lamelliform, toleral)ly broad, and composed of two joints ; the first joint 

 is produced anteriorly into a narrow appendage bearing two apical and marginal setaj ; 

 the second joint is provided with five or six slender bristles on the distal half of the 

 outer margin and apex (fig. 7). 



Caudal rami short, ovate ; a tolerably stout spine springs from a notch near the 

 middle of the outer margin, and there are also one elongate and three short setaj round 

 the distal end of each ramus (fig. 8). 



Habitat. — Scotia Bay, South Orkneys, obtained in siftings from some dredged 

 material collected in June 1903 ; Station 325, 60° 43' 42" S., 44° 38' 33" W. 



Remarks. — The species described above may be distinguished by the peculiar 

 structure of the fifth pair of thoracic legs, as well as by the form and armature of the 

 caudal rami. 



Genus ParalteutJia, new genus. 



Definition. — Similar to Alteutha, Baird, in its general form and in its cephalo- 

 thoracic appendages, except that the inner ramus of the first pair of swimmmg feet 

 consists of two instead of three joints ; and the lateral margins of the second joint of 

 the fifth pair are parallel, or nearly so, while the distal extremity of the joint is obliquely 

 truncated. 



ParalteutJia typica, new species. (PI. X. figs. 16-25.) 



Female. — Body depressed, expanded laterally, as in Alteutha depressa, Baird. 

 Length of the specimen represented by the drawing (fig. 16), 16 mm. 



Antennules nine-jointed, as in Alteutha depressa. Outer ramus of the antennae 

 small and biarticulate, but the end joint is very minute. 



Mandibles with the masticatory end narrow and truncated, biting edge obscurely 

 dentate. Second maxillipeds elongated, each provided with a tolerably large and 

 powerfully clawed hand (fig. 20). 



First pair of thoracic legs elongated and moderately stout, inner ramus not much 

 shorter than the outer, and composed of two subequal joints (fig. 21). The next three 

 pairs long and slender, and furnished with long slender marginal spines (fig. 22). 



Fifth pair stout, two-jointed ; the first joint is short, but the second is tolerably 

 elongated, and about four times as long as broad ; its margins are nearly parallel, and 

 its distal extremity truncated and. armed with three stout spines, the inner one being 

 the largest. There are also two short spines on the inner margin, one near the middle 

 of the joint, the other near its distal end. The first joint is also provided with a few 

 long seta3, as shown in the drawing (fig. 24). 



Caudal rami short and subquadrangular in outline. A short, stout spine springs 

 from a notch on the outer margin of each ramus, and there are also a few small 

 apical spines. 



(ROY. SOC. EDIN. TRANS., VOL. XLVIII, 54G.) 



