Gen. 18. EchinOChereS, Claus, 1889. 



Generic Characters. Body less depressed than in Ascomyzon, the dorsal 

 face of the anterior division being rather strongly vaulted. Tail, as in that genus, 

 composed in female of 3, in male of 4 segments. Anterior antennae much shorter 

 and stouter than in Ascomyzon, though composed of a similar number of articul- 

 ations. Posterior antennae of comparatively feeble structure. Oral cone very short. 

 Mandibles with the palp uniarticulate. Maxillae with one of the setae of the inner 

 lobe excessively developed. Maxillipeds comparatively short and stout. Natatory 

 legs very fully developed, with the rami unusually broad ; their armature about 

 as in Ascomyzon. Last pair of legs with the proximal joint small and indistinctly 

 defined from the segment, distal joint well developed, lamelliform. 



Remarks. This genus was established in the year 1889 by Glaus, to 

 include 2 species found by him as parasites on Echinids. Giesbrecht, however, 

 did not admit this genus, but referred the species to the genus Asterocheres 

 (= Ascomyzon), and this view was also adopted by Scott. On a closer exami- 

 nation of the type species, I find, however, that in some points it differs so con- 

 spicuously from the other species of the genus Ascomyzon, that in my opinion 

 the Clausian genus ought to be supported. As to the term Echinocheres, the 

 same objection could perhaps be urged against it as against the term Astero- 

 cheres; but as in fact both species have hitherto been found exclusively on 

 Echinids, I do not find in the present case any imperious necessity for rejecting it. 

 Only the type species is represented in the Fauna of Norway. 



55. Echinocheres vlolaceus, Claus. 



(PI. LVII). 



Echinocheres nolaceus, Glaus. Halbparasitische Copepoden; Arb. Zool. Inst. Wien, Voll. III. 

 Syn: Asterocheres violaceus. Giesbr. 

 Ascomyzon Thompsoni, A. Scott. 



Specific Characters. Female. Body robust, with the anterior division 

 considerably tumefied and broadly oval in outline. Cephalic segment large and 

 evenly arched in front; rostral prominence comparatively small, though well 

 defined; lateral edges of the segment inflexed. Epimeral parts of the trunk- 

 segments rounded off at the end; penultimate segment, as usual, much smaller 

 than the preceding one; last segment still smaller. Tail comparatively short, 

 with the genital segment gradually widening in front, and having the lateral edges 

 very finely ciliated; anal segment smaller than the preceding one. Caudal rami 

 about the length of the anal segment and slightly divergent; apical seise com- 

 paratively short, the 2 middle ones rather thicker, but not much longer than the 



