i8 STALK-EYED CRUSTACEA 



slender and retractile. Praocular spine usually wanting, 

 postocular usually distinct. Basal joint of external 

 antennas not narrowing distally. The fourth joint of 

 the external maxillipedes is either truncated and 

 articulated with the next joint at its antero-internal 

 angle, or elongated and rounded at its distal end. The 

 first pair of legs, in the male, small, or has the palm 

 inflated and the fingers acute. Thp walking legs are 

 usually very slender. The abdomen is five to seven- 

 jointed. 



Range. — In all seas, in shallow and very deep 

 water. 



Synopsis of the Genera. 



A. Rostrum a single spine. 



a. Postocular spine developed. 

 a^. Last two joints of walking legs not form- 

 ing hooks. 



a^. Carapace subtriangular. 



a^. Antero-internal angle of fourth joint 

 of external maxillipedes rounded. 



«*. Rostrum directed forwards and laterally. 

 — {Anisonotus.) 



/A Rostrum styliform. — {hiac/widcs.) 



U'-. Carapace subpyriform. 



b^. Antero-internal angle of fourth joint of 

 external maxillipedes prominent and pointed. 



c*. Rostrum directed forwards and upwards. 

 — {AnasiiHKS.) 



B. Rostrum two-spined ; spines diverging. 



b. Rostrum about as long as broad. 



Iiiachoiaes. 



b^. The division between the horns a notch. 



d^. Fourth joint of external maxillipedes broader 



Auisouotits. 



