DACTYLOPUS. 105 



prehensile, first or second joint of the outer branch 

 elongated ; second, third, and fourth pairs with both 

 branches 3- jointed ; fifth pair 2-jointed and usually 

 foliaceous. One ovisac. 



The genera belonging to this sub-family are Dacty- 

 lopus, Thalestris, Westwoodia, Ilyopsyllus (?), Harpac- 

 ticus, Zaus, and Peltidium. The genus Ilyopsyllus is 

 included provisionally only in this group ; its struc- 

 ture has not been fully made out, but the abnormal 

 form of the mandibles and antennae will probably 

 necessitate its removal to some other position. 



Diagnosis of Genera of Harpacticince. 



f f two joints Harpacticus. 



both three f greatly elongated Thalestris. 



n es <{ middle not much ffaliaceous Dactylopus. 



CO 111* . i i , -i ** -*- 



-, n joint ^ longer than | 



of the I thenrstjoint;j elon.-ated, sub- 

 | '> { I outer fifth pair of | falciform, and 



^ (^branch ^ feet ^ strongly spined Peltidium. 



the outer f one joint ; C two-branched Westwoodia. 



branch | mandible- < 



composed of { palp (. simple, bisetose Ilyopsyllus. 



three, the 

 inner of ^two-joints Zaus. 



Genus 24. DACTYLOPUS, Glaus (1863). 



Body elongated, more or less cylindrical; first pair 

 of antennae usually 5 9-jointed ; in the male genicu- 

 lated ; inner branch of the second pair of moderate size, 

 2- or 3-jointed. Maxilla-palp well developed, the 

 basal portion numerously clawed and having one or 

 two lateral processes ; mandibles well developed, the 



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