1178 THE VOYAGE OF H.M.S. CHALLENGER. 



more striking, the differences are numerous. The Kerguelen species is not so Corophium- 

 like, the back being less broad ; the lower antennas are less strikingly pediform ; the hand 

 of the first gnathopods is distally narrower ; at least Mr. Haswell says of his species, 

 " The anterior gnathopods might be described as very imperfectly subcheliform — the 

 propus having a small lobe at the base of the dactylus." In the Kerguelen species the 

 fingers in both pairs of gnathopods are more important, the first perseopods have the third, 

 fourth, and fifth joints more developed in comparison with the first, in the third perseopods 

 the first joint is much less narrowed below, and in the fifth less expanded below, than in 

 the Australian species ; in the latter species there is in the peduncles of the pleopods an 

 apical prolongation on the inner side ; and the telson, which is wider at the base than the 

 length, has the centre of the distal margin convex instead of concave. 



Genus Camacho, n. gen. 



Mandibles with cutting edge and secondary plate dentate ; spine-row of numerous 

 denticulate spines ; molar tubercle large and prominent ; palp three-jointed, the third 

 shorter than the long second joint. 



Lower Lip with both pairs of lobes large ; the mandibular processes narrow, 

 divergent. 



First Maxillae with the inner plate small, carrying a single seta ; eleven spines on 

 the outer plate. 



Second Maxillse. having a long fringe of setae on the inner side of the inner plate. 



The Maxillipeds with spine-teeth fringing the inner margin of the outer plates ; the 

 finger of the palp having a short ungual spine, so as to appear unguiculate. 



Upper Antennse with the first joint elongate. 



The First and Second pairs of Gnathopods similar, elongate, with the wrists long, the 

 hands long-oval, subchelate. 



All three pairs of Uropods biramous, the rami in the first and second pairs subequal, 

 in the third pair very unequal, the outer not large, but much larger than the minute 

 inner one ; the peduncle strongly dilated on the inner side. 



The Telson tending to circular, not reaching beyond the peduncles of the third 

 uropods. 



The body elongate, little compressed ; the side-plates shallow, not close set. 



This genus seems to have some affinity with Haplocheira, Haswell, the mandibles 

 being in close agreement, and the rami of the third uropods not dissimilar ; the widened 

 peduncles of the third uropods recall those of Siphoncecetes, Kr0yer, but in that genus 

 the third uropods are not biramous. 



The generic name is derived from a personage mentioned in Don Quixote. 



