1156 THE VOYAGE OF H.M.S. CHALLENGER. 



The definition which Boeck gave of the Corophidse in 1876 is as follows : — 



"Mandibles with the palp generally three-jointed. 



"First Maxillse with the inner plate small or obsolete ; the palp two-jointed, apically 

 armed with teeth, rarely with slender spines (setis). 



" Second Maxillse more or less broad. 



" Maxillipeds with the outer plate armed on the inner margin with teeth or short 

 spines ; the last joint of the palp apically furnished with spines or unguiform. 



" The body depressed ; the side plates very small. 



" Third Urop>ods uniramous." 



The subfamily Corophinae he defines as follows : — 



" Upp>er Lip broad, apically rounded, and setose. 



" Mandibles strong, apically dentate ; the secondary plate also dentate ; [the 

 molar tubercle strong and prominent] 1 and the lower series of teeth ending in a long 

 plumose seta ; the spine-row composed of few, but broad, apically dentate, spines ; the 

 palp three- or two-jointed. 



" Lower Lip broad, the inner plates strong. 



" First Maxillse having the palp apically armed with strong teeth ; the inner plate 

 small or obsolete. 



" Second Maxillse more or less broad. 



" Maxillipeds broad, strong ; the outer plate armed on the inner margin with teeth 

 or spines ; the fourth joint of the palp apically furnished with two strong spines or 

 unguiform. 



" The Body depressed, broad, robust ; the side-plates small, rigid. 



" The Head dilated. 



" Lower Antennse generally stronger than the Upper, pediform, apically furnished 

 with curved spines (unguibus), in the male very robust. 



" Second Gnathopods generally stronger than the First. 



" Pleopods short, strong ; the peduncle sometimes on the inner side strongly 

 dilated. 



" First and Second Uropods biramous ; the rami little elongate. 



" Third Uropods small, short, broad, uniramous. 



" Telson laminar." 



To include Cerapus, this definition will require to be modified by saying that the 

 Maxillipeds are generally broad, and that the Second Uropods are sometimes 

 uniramous. 



1 There is no equivalent for the hracketed words in' either of Boeck's works, but as the definitions have evidently 

 been copied into the larger work from the smaller and earlier one, the repetition of mistakes after the author's death is 

 not to be wondered at ; the accounts of various species will, I think, justify the mode above adopted of filling up an 

 obvious hiatus. 



