REPORT ON THE CRUSTACEA MACRURA. 707 



This species iu its general characters is very close to Oplophorus typus, only differing 

 in such slight features that it is difficult to consider it as being more than a variety. 



One peculiar feature worthy of notice is the translucent character of the carapace over 

 the branchial region, so much so that the branchial plumes may be seen distinctly through 

 it and their form determined. 



Campylonotus, n. gen. 1 



Carapace longitudinally ribbed, anteriorly produced to a strong, laterally compressed, 

 and deep rostrum, armed on the upper and lower margins with strong teeth ; frontal 

 margin having a first and second antennal tooth strongly developed at the anterior 

 extremity of the longitudinal ridges, which are most conspicuous at the anterior extremity 

 of the carapace. There is no supraorbital or hepatic tooth, and the rest of the carapace is 

 smooth except for a small more or less dentate carina on the dorsal crest. 



The pleon is smooth and the somites subequal, the third being dorsally arcuate and 

 the sixth a little longer than the preceding. 



The telson is long, gradually tapering to a point, dorsally smooth, and laterally 

 compressed. 



The ophthalmopoda are short and have a large subglobose ophthalmus, but carry no 

 distinct ocellus. 



The first pair of antennse is biflagellate, and carries a strong stylocerite that is 

 produced to a sharp point. 



The second pair of antennse carries a long, slender flagellum, and a scaphocerite that 

 is broad, well developed, and strengthened by a longitudinal ridge that traverses the 

 middle of the plate. 



The mandibles are short, robust, and deeply inserted within the oral cavity, have 

 the molar process and psalistoma connected by a serrate ridge, and carry a Inarticulate 

 synaphipod. 



The first pair of gnathopoda has the terminal joints large and reflexed against the 

 inner side of the preceding. The basisal joint carries a long and slender ecphysis, and the 

 coxa a small mastigobranchial plate that supports a podobranchial plume. 



The second pair of gnathopoda is pediform, six-jointed, carries a multiarticulate 

 basecphysis, and the coxa supports a small mastigobranchia but no podobranchial plume ; 

 a small arthrobranchial plume arises from the membranous articulation connecting the 

 leg with the somite. 



The first two pairs of pereiopoda are chelate, the anterior pair being smaller than the 

 second. The three succeeding pairs are simple, and a small rudimentary mastigobranchia 

 that terminates in a strong curved point is attached to the coxa of each pair of pereiopoda 

 excepting the posterior. None of the pereiopoda carry a basecphysis. 



1 zctftKv'ho;, curved ; i/«ro;, back. 



