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



are remarkably long and slender. The upper lateral carina commences near the 

 posterior margin of the carapace, traverses the line between the dorsal and branchial 

 regions, and ends anteriorly near the middle of the orbit. The first antennal tooth, 

 situated at the outer canthus of the orbit, is long, sharp and not confluent with any of 

 the carinse. The second antennal tooth is long, straight, and is continuous with a carina 

 or ridge that extends to the posterior margin. 



The pleon has the first two somites smooth ; the third is carinated, the ridge, which 

 commences abruptly at the anterior margin, is longitudinally fluted and produced to a 

 tooth posteriorly ; the fourth and fifth somites are carinated and produced posteriorly to 

 a tooth parallel with the dorsal surface. The sixth somite is smooth, dorsally slightly 

 fluted longitudinally, as is also the telson, which is likewise laterally compressed ; the 

 longitudinal angle is armed with three small spines and the extremity is tipped with four. 



The ophthalmopoda are short and orbicular. 



The first pair of antenna} carries a stylocerite that reaches considerably beyond 

 the extremity of the ophthalmopod, and terminates in two flagella of unequal size ; the 

 shorter and upper is the more robust, and extends a little bej^ond the extremity of the 

 rostrum ; the inner and lower is more slender, and is about half as long again as the 

 upper. The second pair of antennse is about once and a half the length of the animal, 

 and carries a scaphocerite, that has the margins subparallel, and armed with a tooth on 

 the outer margin that does not reach to the extremity. 



The pereiopoda and other appendages offer no very decided features of specific 

 character. 



This species is represented by fourteen specimens, which were taken off the south- 

 eastern extremity of the Philippine Islands, the largest being 83 mm. long, and one taken 

 off the southern shores of Japan which is only 37 mm. long ; it is, moreover, more 

 slender generally, and has the rostrum relatively longer and armed with ten teeth on the 

 upper margin and thirteen on the under. 



The specific name is derived from the Christian name of Alphonse Mflne-Edwartls, 

 who was the first to define the genus. 



Heterocarpus gibbosus. n. sp. (PI. CXII. fig. 2). 



Carapace having five imperfect carina?. Dorsal carina scarcely visible at the posterior 

 margin, but elevated to a strong crest, armed with six large teeth over the gastric and 

 frontal regions, and produced anteriorly to a long laterally compressed rostrum, directed 

 obliquely upwards, and armed on the upper margin with three small equidistant teeth, 

 and on the lower with eleven or twelve, which diminish in size anteriorly. The lateral 

 carinse are rather elevations than distinct ridges, and are lost before reaching the posterior 

 margin. 



