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selves four times, and concealed beneath the head j first and second 

 joints distally enlarged. An elongate mandibular appendage. Gna- 

 thopoda short, and complexly chelate. Third and fourth pairs of tho- 

 racic feet having the coxse dilated ; the fifth pair small. Fourth and 

 fifth abdominal segments fused into one ; sixth small. Caudal appen- 

 dages long, biramous. Telson cylindrical, long. 



This genus exhibits a remarkable blending of the characters of Oxy 

 cephalus and Bhahdosoma. The general form of the animal is that of 

 Oxycephalus ; the short neck and elongated rostrum show a tendency 

 toward Bhahdosoma. Both pairs of antennae, the abdomen, and caudal 

 appendages are identical with the corresponding parts in the latter ge- 

 nus; while the three posterior thoracic feet are a repetition of the for- 

 mer. A similarly elongated mandibular appendage is observed in Bhah- 

 dosoma whitei. 



LEPTOCOTIS SPINIFERA, n. sp. 

 Head long, with the rostrum longer than the thorax ; vertical diam- 

 eter of the head greater posteriorly than anteriorly ; the superior sur- 

 face on a higher level than the dorsum of the thorax ; abruptly con- 

 stricted behind the eyes and in front of the first thoracic segment; 

 the inferior border slightly convex ; the under surface hollowed out on 

 each side anteriorly in the form of fossae for the reception of the su- 

 l)erior antennae ; supra-fossal margin arched and slightly elevated ; ros- 

 trum long, acute, slightly arched. Eyes covering the whole of tbe 

 lateral and dorsal surfaces of the head posterior to the superior an- 

 tennae. Superior antennae sickle-shaped ; peduncle broad, three-jointed, 

 with margins densely hairy, particularly the inferior margin ; second 

 joint short; the third longer than the first and second together, com- 

 pressed, bent forward at its articulation with the second joint, and its 

 anterior inner apex produced as a long, acute process, which is almost 

 at a right angle with the main portion of the joint; base of process 

 enlarged; flagellum articulating with the anterior surface of the base 

 of the process, and shorter than the process, biarticulate, each ar- 

 ticulus having three or four long auditory cilia. Inferior antennae five- 

 jointed, folded upon themselves four times, and hidden in a groove on 

 the under surface of the head ; the first, second, and third joints equal 

 in length ; the first and second enlarged at their distal extremities; fourth 

 joint a little shorter than the preceding ; fifth very short, with one or two 

 auditory cilia at its apex. The mandibular appendage long, slender, 



