96 BULLETIN OF THE ESSEX INSTITUTE. 



First pair of feet larger than the second, the first pair 

 being sub-chelate, the second non-chelate, and with sim- 

 ple carpus. Antenniilffi biflagellate, the inner flagellum 

 about half the length of the outer. Antennae long ; an- 

 tennal scale small, not reaching to the external spine. 



This genus resembles the Crangoninse in the larger 

 first pair of pereiopoda ; in the sul)-chelate character of 

 the anterior hand, and the non-annulate carpus of the 

 second pair of pereiopoda. It dififers, however, from this 

 sub-fann'ly, and from all the CrangonidoB as limited by 

 Dana, in the excavate mandible and in the possession of a 

 mandibular palpus. The cutting edge of the mandible 

 recalls somewhat that of the Atyidee, but the palpus is 

 not present in that family. Mandibular characters also 

 exclude it from all known Palasmonida?. Subsequent 

 investigations may show that it will be necessary to erect a 

 new 'family' for its reception. 



jSTaushonia crangonoides n. sp. Carapax somewhat 

 cylindrical, depressed in front, the rostral region being 

 down curved. The I'ostrum flattened, tip broadly trian- 

 gular, extending forward slightly beyond the eyes. Su- 

 pra-orbital and antennal spines present ; branchiostegal, 

 hepatic and pterygostomian spines lacking. Cervical 

 groove well marked in the middle but not reaching the 

 antero-laleral margin of the carapax. A well-marked 

 impressed line extends from the antero-external angle on 

 either side to the posterior margin of the carapax. With 

 these exceptions the carai)ax is smooth and is without 

 pubescence. The abdomen is about a third longer than 

 the carapax ; is smooth and without carinas, spines, etc. 

 The telson is a third longer than broad, its tip regularly 

 and broadly rounded, with a spine at each external angle. 

 The eyes are on short peduncles, not visible from above, 

 and with a minute pigment spot. The antennuloe are 



