36o STALK-EYED CRUSTACEA 



d^. Fingers move in a horizontal plane. Right hand 

 in the form of an operculum. — {Pylopagunis^ 

 c^. Abdomen atrophied. 

 e^. Two last pairs of legs monodactyle, — {Ostraconotus?) 



b. Fourth pairs of legs subchelate. Males with a 

 protruded vas deferens. Branchial laminae have a bifid 

 extremity. 



dP-. Vas deferens opens on the left side. 

 f^. Vas deferens spiral. — {Spiropagiirus.) 

 g\ Vas deferens curved. — {Anapagunis.) 

 ^-. Vas deferens opens on right side. 

 h^. Vas deferens c\xvvtd.-^{Catapag7ir?{s.) 



B. First and second abdominal segments provided 

 with genital appendages (first segment only in the female). 



c. Eye-stalks slender ; basal scales far apart. Anten- 

 nules long. 



P. Flagellum of external antennae usually short and 

 hairy ; chelipedes subequal, or equal ; fingers move in a 

 horizontal plane. Penultimate pair of legs not chelate. — 

 {Pagaristes.) 



j^. Flagellum of external antennae long and naked. 

 Chelipedes unequal, right largest ; fingers move in an 

 oblique plane. Penultimate pair of legs subchelate. — 

 {Sympagiirus.) 



C. First abdominal segment only, in the male, provided 

 with genital appendages. 



k^. Rostrum wide and obtuse. Eye-stalks strong, with 

 dilated extremity, shorter than antennulary peduncle. 

 Penultimate pair of legs subchelate, last pair chelate. — 

 ( Tojuopagunis.) 



II. Abdomen not spirally twisted, composed of distinct 

 movable segments that are usually calcified. — {Caticellincu, 

 Dana.) 



