274 SEXUAL DIMORPHISM 



these a pair of small jointed appendages. Dohrn l describes 



'^^ 



Fig. 30. Gnathic/, maxillaris, a British Isopod. A, adult male ; B, adult male, ventral 

 surface ; C, adult female ; D, larva. 



these as two distinct pairs of oral appendages, while Sars 



1 UnUrs. uber Bau und Entwick. der Arthropoden, Leipzig, 1870. 



