324 



CRUSTACEA. SCHIZOPODA 



in character, with the exception that, in some forms, the 

 first one or two pairs may serve as maxillipedes. The 

 abdomen is long and slender; its five anterior pairs of 

 appendages are biramous swimming legs, whilst the sixth 

 pair form with the telson a tail fin. The compound eyes 

 are stalked. 



Fig. 141. A Recent Schizopod — Nyctiphanes norvegica. (After Watase.) 

 The black dots indicate the phosphorescent organs ; the gills are 

 seen between the thoracic and the abdominal appendages. Slightly 

 magnified. 



Recent work tends to show that the Schizopoda do not 

 constitute a natural group, since of its two main divisions 

 one appears to be related to the Pecapoda, whilst the 

 other approaches more nearly the Cumacea, Isopoda, and 

 Amphipoda. Since, however, the affinities of a number 

 of fossil schizopod-like forms have not yet been satis- 

 factorily determined, it will be convenient to retain for 

 the present the group Schizopoda. 



Living Schizopods, with the exception of a species of 

 Mysis, are marine, and many of them are pelagic. The 

 fossil forms which have been referred to this group are 

 found mainly in the Carboniferous rocks, especially in the 



