310 A HISTORY OF RECENT CRUSTACEA 
Family 8. —Diastylide. 
The first antennez are more or less unlike in the two 
sexes, the flagella unequal, the smaller being three-jointed 
in the female. The anterior branch of the mandibles has 
Fic, 27.—Diastylis Goodsiri, lateral 
view of female [Hansen]. 
Fic. 26.—Diastulis Goodsiri, dorsal view 
of female [Hansen], 
a dense series of lateral spines. The epipod of the first 
maxillipeds has the branchial sacs arranged more or less 
spirally. The third maxillipeds have the second joint very 
large and curved. ‘The first two pairs of perezeopods in the 
female and the first four in the male have well-developed 
swimming-branches. There are only two pairs of pleopods 
in the male, and of these the second is sometimes imper- 
fectly developed. The uropods have the inner branch 
two- or three-jointed. The telson is distinct, generally 
narrowed terminally, with only two spines at the apex. 
The family includes three genera. 
Diastylis, Say, 1818, is the earliest in date of the 
Cumacean genera, and in Lepechin’s Oniscus scorpioides, 
