472 STALK-EYED CRUSTACEA 



First two pairs of legs subequal, small. — {Tropio- 

 caridcB). 



f. The first pair of maxilli- 

 pedes two-branched. The finger 

 and thumb of the two anterior Tropiocarida:. 



pairs of legs are very long and 

 feeble. — {Stylodactylidci). ^w^-^^Z^IH^::^- " 



B. The three posterior pairs ^ 



/•I 1 i. J Stylodactylidcc. 



of legs are very short and some- -^ 



times imperfectly developed. — {^PasiphmdcE^ 



Family I. Atyidae. 



Atyida; . . . Spence Bate. 



Carapace dorsally smooth, rounded, and produced to 

 a flattened rostrum, not laterally compressed. Abdomen 

 short and robust. Internal antennae with a spine on 

 outer side ; external antennae with a short basal scale. 

 Mandibles with a molar process and cutting margin, but 

 no palp. External maxillipedes four-jointed and pediform. 

 First and second pairs of legs with pincers ; finger and 

 thumb spoon-shaped. Three last pairs of legs simple. 

 Abdominal appendages two-branched. Swimming organ 

 well developed. Telson flattened, truncate. 



I. Atya. 



Atya . . . . Leach, Latreille, Desmarest, Roux, 

 Wiegmann, H. Milne Edwards, 

 A. Milne Edwards, Spence Bate. 



Atys . . . . Leach. 



Atyoida . . . Randall. 



Animal laterally compressed, dorsally smooth. Ros- 

 trum in a line with the carapace, flat and broad at the 



