DISTINCTIVE CHAHACTEUS UF THE (,'HAYFISH. 28o 



spine. The elevation itself may be distinguished as the 



j)ost-orhital ridge. The flattened surface of this ridge is 



mai'ked by a longitudinal depression or groove. Tlie 



A B C 



Fir. (il.— a, D, & G.A.<itneus tiin-mtu/w ; B, E, & H, .1. nohi/i.s-; C, F, & 

 I, .1. nifjrr.^cciix (nat. size). A — C, Dorsal views of carapace; D — F, 

 side vie\v.s of third abdoraiual somites ; G — T, Dorsal views of telson. 

 (I, h, post-orbital ridge and spines ; c, brauchio-cardiac grooves 

 inclosing the areola. 



