CALIG1D.E. 213 



Genus ? ECHTHROGALEUS, Steenstrup & Liitken, $ . 



Male. General form that of a Caligus, but the penulti- 

 mate segment of the metasome completely separated from 

 the cephalosome. No lunules or frontal sucking-discs. All 

 first four pairs of feet two-branched ; both branches of first 

 pair two-jointed; inner branch of three following pairs two- 

 jointed, and outer branch three-jointed ; all branches of the 

 feet setose. 



This Crustacean is near to Nogagus, but in the type species 

 of that genus, Nogagus Latreillii, Leach, both branches of all 

 the two-branched feet consist of two joints (vide Steenstrup 

 & Liitken, pi. ix. fig. 18). 



Heller (Reise ' Novara,' Crustaceen, p. 197, pi. xx. fig. 3) 

 describes a parasite from New Zealand which he considers to 

 be the male of Echthrogaleus braccatux (Dana), in company 

 with which it was found. The species described below is 

 undoubtedly congeneric with the male described by Heller. 

 We have only one British Eclithrogaleus, is this then its male? 

 The future must decide. It has not yet, so far as we know, 

 been found in company with Echthrogaleus coleoptratus, nor 

 even infesting the same species of fish. 



ECHTHROGALEUS LUTKENI (Norman). (PI. XXII. figs. 1-9.) 



1869. Nogagus LMkeni, Norman, " Last Report Dredging Shet- 

 land," Brit. Assoc. Kept, for 1868, p. 300. 



The cephalosome is much rounded, its breadth much 

 greater than the length ; the hinder corners of the lateral 

 arese incurved, well rounded, and reaching backwards to the 

 end of the first of the two exposed segments of the metasome. 

 First segment of metasome with lateral expansions broader 

 and longer than in the following- short segment. The urosome 

 consists of three segments ; the first, or genital segment, is 

 subqnadrate with slightly arched sides, longer than broad ; the 

 second segment very short, the terminal rather broader than 

 long ; the uropodal laminae are as long as the two preceding 

 joints, and of ovate form. 



The antennules (fig. 2) have the first joint much longer 

 than the second ; the second joint has one spine on the hinder 

 margin. The antennae (fig. 3) have the penultimate joint 

 stout, the last long and gradually attenuated, only very 

 slightly curved, bearing a single seta on the inner face. The 

 first maxillipeds (fig. 4) have the claws setose. The second 

 maxillipeds have the terminal joint very broad and stout, 

 obliquely truncate distally, with a nodule, and areolated disk 



