116 PROCEEDINGS OF THE NATIONAL MUSEUM. tol. 37. 



MICROPROTUS, new genus. 



Head with short truncated rostrum and without eyes. First pair 

 of antennae with the first article of the first pair of antenna? produced 

 at the outer anterior angle; flagellum multi-articulate. Second 

 antennae with the flagellum multi-articulate. 



Molar expansion of mandibles well developed. Palp three 

 jointed. First four segments of thorax provided each with three 

 long dorsal spines, one in the median line, and one on either side, at 

 the antero-lateral angle ; the last three segments provided with three 

 long spines, one median and one on either side, all close together, and 

 the antero-lateral angles produced in a long spine on either side. 



The epimera of the second, third, and fourth segments of the 

 thorax produced in two spines, the anterior one being longer. The 

 epimera of the last three segments, in the form of small rounded 

 lobes, situated on the posterior half of the segment. 



Abdomen with the lateral margins produced in two sjDines on 

 either side, and the posterior margin produced in two spines. 



Uropoda consisting of a peduncle and two branches. 



The first pleopoda of the male have the distal extremity of the 

 peduncle produced. 



First pair of legs small, short, and feeble; the following six pairs 

 robust and similar in character. The second, third, and fourth pairs 

 gradually increase in length. Dactylus bi-unguiculate. 



This genus has affinities Avith the Munnopsidw. The short, trun- 

 cated rostrum, the absence of eyes, the small and short first pair of 

 legs as compared with the three following pairs and the form of the 

 first article of the first pair of antenna? are characters similar to 

 those found in that family. The absence of natatory legs, the general 

 form of the body and the style of uropods, however, are characters 

 referable to the Janiridce. 



The type of the genus is Microprotus ccecus, the description of 

 which follows: 



MICROPROTUS C^CUS, new species. 



Head, with the anterior margin almost straight, and joroduced in 

 the middle in a small, truncated rostrum. Eyes wanting. First paiv 

 of antenna^, with the first article large and produced at the outer an- 

 terior angle; second article about half as long as the first and only 

 half as wide; third article more slender than the second and a little 

 longer. Second antennae with the second article of the peduncle pro- 

 vided with a long spine; the third article is provided with a long 

 spine on the underside; the fourth article is provided with two long 

 spines, one above and one on the unders^le ; the fiftli and sixth articles 

 are long and slender and are not armed. The flagellum is elongate 

 and multiarticulate. 



