24 AY. M. TATTERSALL. 



(Figs. 1, 2 and 3) small, united at their base into a thick flattened pad, from 

 the anterior part of which proceed two thin, short, sub-triangular, slightly-diverging 

 lappets, which do not reach the middle of the basal joint of the antennular peduncle ; 

 visual elements entirely absent. 



Antennular peduncle (Fig. 2) short and stout, its three joints sub-equal in length 

 and quadrangular in outline ; basal joint, with a single long seta on its internal distal 

 corner, and a more or less continuous submarginal row of setae across the anterior 

 dorsal region ; second joint with about seven long stout plumose setse on its inner 

 margin and two or three long setae on the outer distal corner ; third joint with about 

 eleven long stout plumose setse on the inner margin. On the dorsal surface of the 

 basal joint, partly concealed by the eye in dorsal view, is an organ of rather 

 problematical function (Figs. 2, 4 and 5). It appears to consist of a shallow depression 

 bounded by a raised ridge marked with pigment, and overhung by a membranous flap, 

 which apparently rises from its posterior border. The flap only imperfectly covers the 

 depression. In the preliminary notice of this collection it was suggested that this 

 organ might prove to be auditory in function, but under moderately high powers of 

 the microscope no otoliths or even sensory hairs could be distinguished in the 

 shallow pit. 



Antcnnal peduncle longer than the antennular, and considerably more slender ; 

 distal joint shorter than the preceding. 



Antennal scale (Fig. 2) lanceolate in shape, about three-and-a-half times as long as 

 broad, apex evenly rounded, the whole of the inner margin and distal third of the 

 outer margin setose ; proximal two-thirds of the outer margin devoid of setae, but 

 armed with eleven strong spines, the proximal one of which is the shortest, and is 

 situated at the end of the proximal quarter of the outer margin, the spines increasing 

 in size distally ; spine on the outer distal corner of the basal joint short, but 

 prominent. 



Mandibles (Fig. 6) with the cutting edge prominent and molar process well- 

 developed and rather long ; between the cutting edge and the molar process is a 

 single spine-like seta, and in the left mandible a lacinin mobilis in addition; palp 

 (Fig. 7) rather long and powerfully developed, terminal joint shorter than the 

 penultimate, both joints armed on both outer and inner margin with numerous long 

 and rather stout setse. 



First maxilla (Fig. 8) having the outer lobe much larger than the inner, and 

 armed at its apex with about thirteen spines, behind which is a row of five plumose 

 setae ; inner lobe armed at its tip with four long plumose setae. 



Second maxilla (Fig. 9) consisting of the usual three lobes, a two-jointed palp 

 and outer setiferous plate, the setae arming the appendage being numerous and 

 rather strong. 



First thoracic limb (Fig. 10) short and stout, devoid of exopod, but with well- 

 developed epipod ; third joint small ; fourth joint with numerous setre and a row of 



