110'2 THE VOYAGE OF H.M.S. CHALLENGER. 



usual pair of dorsal setae or spines. The animal covered in many parts of the mouth- 

 organs, as well as the exterior, with dark stellate markings, an enlarged figure of one of 

 which is oiven in the right Land lower corner of the Plate. 



Eyes of very peculiar shape, lageniform, occupying the front of the lateral lobes, and 

 produced upwards in a narrow neck round the part of the concave margin between the 

 rostrum and the lateral lobes. 



Upper Antennse. — The third joint about equal in length to the first; the principal 

 flagellum of seventeen joints ; the secondary flagellum of six joints together equal to 

 the first five of the principal. 



Lower Antennas. — The third joint a little upward bent ; the fourth and fifth joints 

 equal or nearly so ; the flagellum of ten j oints. 



Mandibles. — On the left mandible there are twelve spines in the spine-row ; the 

 secondary plate of the right mandible has four clearly cut teeth followed by one or two 

 denticles ; the second joint of the palp has only two groups of spines near the outer 

 margin ; the third joint is as long as the second and distally a good deal broader, with 

 spines singly or in groups at five points near the outer margin. 



First Maxilla?,. — The apex of the inner plate is still more narrowly produced than in 

 the other species ; the ten spines on the apex of the outer plate are as in that species. 



Second Maxilla?. — The row of plumose setae on the inner plate numbers twenty-six ; 

 the distal margin is flattened and more than half of it devoid of spines. 



Maxillipeds. — On the outer plates the inner margin has six spine-teeth, the distal 

 margin has six spines, of which the first is a strong spine-tooth, the three outermost are 

 setiform, the other two of intermediate character; the first joint of the palp has slender 

 spines on the outer apex ; the second joint has a similar group, but no others on the outer 

 margin ; the third joint has surface spines at about the middle ; the spine at the tip of 

 the finger is a little shorter than the body of the finger. 



First Gnathopods. — The side-plates are produced at the lower front corner and reach 

 the base of the lower antennas. The finger reaching beyond the palm. 



Second Gnathopods. — The side-plates directed a little forwards. The branchial 

 vesicles (not observed in the other species) very small and narrow. The marsupial plates 

 much longer and broader than the branchial, gradually narrowing downwards, surrounded 

 by long setse. The first joint with only a few setse on the convex hind margin ; the 

 hand oblong, but slightly narrowing towards the palm and with the front margin convex, 

 the hind margin serrate, produced into a long tooth at the commencement of the palm, 

 which is not very oblique, irregularly convex, and crenate ; the much-curved finger 

 reaches with the nail quite beyond the process which defines the palm ; it has just 

 within the inner margin a beaded appearance, seemingly caused hy the presence of nine 

 or'ten minute spine-teeth which do not project beyond the margin. 



Fourth Pereeopods. — The first joint pear-shaped, with some spinules along the almost 



