EEPORT ON THE AMPHIPODA. 67i^ 



from so great a depth as 1900 fathoms, but that the Stations at which the two species 

 were obtained are separated by nearly half the circumference of the globe is a circum- 

 stance not open to any such explanation. The first pair of side-plates, the hands of the 

 second gnathopods, and the postero-lateral angles of the third pleon-segment are service- 

 able marks for distinguishing the two species. 



Orckomene cavimanus, n. sp. (PI. XXIL). 



Rostrum obsolete, lateral lobes of the head produced, much rounded ; postero-lateral 

 angles of the third pleon-segment scarcely rounded, fourth pleon-segment with a dorsal 

 depression, and the hinder part of the dorsal margin forming a sharpened point slightly 

 tip-tilted and raised above the succeeding segment ; sixth segment ridged on each side 

 of the telson. 



Uyes large, placed near the front of the head, wider below than above. 



Upper Antennse. — First joint tumid, second and third very short, third excavated 

 below s flagellum of thirteen joints, the first as long as five of the following joints together, 

 the brush of cylinders in ten or eleven rows, cylinders on many of the other joints also ; 

 secondary flagellum of five joints, of which the first is much the longest. 



Loiver Antennse. — Gland-cone moderately prominent but small, third joint longer 

 than the composite first and second, and as long as the fifth joint ; fourth joint longer 

 than the fifth, both being furred on the upper margin ; flagellum of fifteen or sixteen 

 small joints in the female specimen here described. 



Epistome prominent, with a rounded lobe curving down just over and in front of the 

 top of the upper lip. The Plate gives a figure representing the epistome between the 

 palps of the two mandibles, with the upper lip, two mandibles, and lower lip in position ; 

 the left mandible with its secondary plate is shown projecting a little in advance of the 

 right mandible ; the inner side of the right mandible is figured on the other side of 

 the Plate. 



The Mandibles and Lower Lip resemble those of Orchomene musculosus, luit with 

 the parts adjacent to the molar tubercle less furred, and the palps more slenderly built, 

 the third joint being also shorter in comparison with the second. 



First Maxillw similar to those of Orchomene musculosus, but the inner plate more 

 elongated. 



Second Maxillse. — Outer plate broader than inner, not very much longer, spine- 

 fringed border not very oblique ; armature of inner plate as in Orchomene musculosus. 



Maxillip)eds narrow, inner plates reaching nearly as far as the apex of the first joint of 

 the palp, with three teeth on the straight apical margin ; outer plates scarcely reaching as 

 far forward as second joint of palp, with fourteen small nodulous teeth on the inner, and 

 reaching round to the apical margin, with two much larger teeth on the outer part of 



