300 STALK-EYED CRUSTACEA 



the pterygostomian region and in front of the first pair 

 of legs, or, more rarely, at the antero-lateral angles of 

 the palate. Branchije six to nine. The fifth joint of 

 the external maxillipedes is articulated either at the 

 antero-internal angle, at the antero-external angle, or at 

 the distal extremity of the fourth joint, and is frequently 

 concealed beneath it. 



The verges of the male exserted either from the 

 sternal surface, or more usually from the base of the last 

 pair of legs, which is either gressorial, natatorial, or feeble, 

 and raised upon the dorsal surface of the carapace. 



Range. — At great depths of the ocean or at moderate 

 depths, but not shallow-water forms, in temperate and 

 tropical seas. 



Family I. Calappidse. 



Family II. Matutidse. 



Family III. Leucosidse. 



Family IV. Dorippidae. 



Synopsis of the Families. 



I. Posterior legs normally developed. 



A. Afferent channels to branchiae open behind the 

 pterygostomian region in front of first pair of legs. 



1. The fifth and following joints of the external 

 maxillipedes not completely hid behind the fourth joint. 

 — ( CalappidcB. ) 



2. The fifth and following joints of the external 

 maxillipedes completely concealed behind the fourth 

 joint. — {Matudidcu.) 



B. Afferent channels to branchiae open at the antero- 

 lateral angles of the palate. 



3. The fifth and following joints of the external 



