1194 THE VOYAGE OF H.M.S. CHALLENGER. 



uropods having only an oval plate not so long as the telson, but reaching a little beyond 

 it, with some spinules on the border. 



TJie Telson rather broader than long, very much rounded, with a broad laminar 

 projection on the upper surface beyond the centre, not reaching the distal margin, 

 carrying two spines. 



Length. — The specimen, in the position figured, measured, in a straight line from the 

 front of the head to the back of the third pleon-segment, a little over one-fifth of an 

 inch. 



Locality. — The single specimen, perhaps not adult, was labelled as obtained from 

 Chelonia imbricata, Atlantic. 



Remarks. — The specific name is taken from the animal on which the specimen was 

 found lodging. 



This species differs from Platophium danse in having the palps of the mandibles and 

 the maxillipeds less elongate, as well as in other points of more obviously specific Value, 

 but the general character of the mouth-organs and antennae, together with the agree- 

 ment in the structure of the pleon, seemed to warrant its being placed in the same 



genus. 



Platophium inconspicuum, n. sp. (PI. CXXXI.). 



Rostrum inconspicuous ; the outer corners of the front of the head rounded ; back of 

 the animal broad at the centre of the perseon ; pleon closely flexed ; first three segments 

 of the pleon with the postero-lateral angles rounded ; the fourth segment of the pleon 

 longer than any other segment, very much longer than the fifth and sixth segments 

 united ; dark pigment-flakes retaining their colour in the spirit-preserved specimen. 



Eyes broad oval, comparatively large, with numerous short ocelli. 



Upper Antenna;. — First joint rather thick, shorter than the head, carrying a few 

 slight spines. The remaining joints broken off. 



Lower Antennas. — First joint a little expanded, the first and second joints short, the 

 gland-cone small ; the third joint thick, little longer than broad, with a few slender 

 spines ; the other joints missing. 



Upper Lip unsymmetrically bilobed. 



Mandibles. — The cutting edge narrow, sharply toothed with five or six teeth ; the 

 secondary plate with four or five teeth which are thin and sharp ; the spine-row with 

 two rather broad denticulate spines ; the molar tubercle broad, with strongly dentate 

 crown, and a small laminar distally denticulate process on the edge of it ; the first joint 

 of the palp much longer than broad, narrow at the base, widening distally ; the second 

 joint about twice as long as the first, with three or four spines on and near the front 



