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allied genus. The present form is indeed, easily distinguishable from any of the 

 species of that genus, and is, moreover, in the living state at once recognised 

 by its peculiar colour, which has also been mentioned by Scott 



Occurrence. I have met with this handsome form occasionally in 2 or 

 3 places on the west coast of Norway in depths ranging from 20 to 50 fathoms. 



Distribution. British Isles (Brady), Madeira (Thompson). 



Fam. 8. Artotrogidae. 



Characters. Body very broad, more or less clypeiform, with the 2 

 posterior trunk-segments imperfectly developed. Tail quite short, and composed 

 in female of 4, in male of 5 segments. Antennae and oral parts on the whole 

 built on the same type as in the Dyspontiidce. Only 3 pairs of natatory legs 

 present, the 4th pair being wholly absent Last pair of legs not defined from 

 the corresponding segment. Ovisacs in female more or less concealed beneath 

 the body. 



Remarks. This family, as here defined, does not answer at all to the 

 family Artotrogidce of Brady, which, like the family Asterocheridce of Giesbrecht, 

 was established to include all the siphonostomous Cyclopoida. In the restriction 

 here adopted, this family only comprises 2 genera, viz., Artotrogus Boeck and 

 Dystrogus Giesbrecht, both of which agree in one very essential character, viz., 

 in the total absence of the 4th pair of legs, in this respect exhibiting an approach 

 to the next family, the Cancerillidce. The exact comparison of these 2 genera 

 is rendered somewhat difficult by the circumstance that of the one (Artotrogus) 

 we only know the female sex, of the other (Dystrogus) only the male sex. It 

 is evident, however, that they represent two distinct generic types. 



Gen. 33. ArtOtTOgUS, Boeck, 1859. 



Generic Characters. Body greatly expanded, rounded in form, with the 

 epimeral lappets of the cephalic segment and the 2 anterior trunk-segments well 

 developed, imbricate. The last 2 trunk-segments almost wholly concealed, with 

 no epimeral lappets. Tail very short, projecting only slightly beyond the anterior 



