TAltEN OFF NORTHUMBERLAND AND DURHAM. 215 



rather longer than broad (Plate 4, fig. 6), the principal tail 

 seta about half as long as the body. Antennules short and 

 moderately stout (Plate 3, fig. 11), equal in length to the 

 antennae, eight-jointed and densely setiferous; antennae (Plate 3, 

 fig. 12) bearing a small one-jointed secondary branch ; posterior 

 footjaw (Plate 3, fig. 14) having an angular subquadrate hand 

 with a flexuous terminal claw and two marginal setae, the 

 basal joint also bears two or three setae near its distal 

 extremity. Inner branch of the first pair of swimming feet 

 (Plate 3, fig. 13) slender, elongated, its first joint somewhat 

 longer than the entire outer branch, the two distal joints 

 short and nearly equal, and bearing two long slender apical 

 setas ; outer branch three-jointed, joints nearly equal, setose on 

 the outer margin, and with a long spine-like seta at each apex, 

 the last joint bearing also slender terminal setae; second, third, 

 and fourth pairs (Plate 4, fig. 3) composed of two equal three- 

 jointed branches ; fifth pair with a very broad and shallow 

 basal joint (Plate 4, figs. 4, 5) and an elongated narrow distal 

 joint, which is abruptly tapered at each extremity, bearing 

 several marginal setae and, near the apex of the inner margin, 

 a single spine-like seta : the basal joint is armed with a long 

 seta at its inner angle, following which is a stout spine 

 divided at its apex into three hair-like processes, then a 

 shorter lancet-shaped spine, followed by a still smaller one of 

 the same type, and one or two very small hairs ; the outer 

 angle bears the usual seta. Length, exclusive of tail setje, 

 0*38 mm. (i-66th in.). 



This species, of which only one example was taken, is very 

 similar in most respects to Delavalia inimica, T. Scott,* and 

 had it not been for the equality of length in the branches of 

 the swimming feet I should have been disposed to refer it to 

 that species, though there are in addition to this character 

 some other rather important differences. The antennule 

 in Dr. Scott's species seems to be longer, the inner branch 

 of the first foot considerably stouter, and the armature 



* Fifteenth Annual Report of the Fishery Board for Scotland (1897), p. ISO, 

 pi. 1, figs. 1-9. 



