ERGASILOIDEA. 



1311 



Tribe I. ERGASILOIDEA. 



The Ergasiloidea may contain different families corresponding to 

 the families among the Cyclopoidea. At present we recognise only 

 three. One, MosrSTRiLLiDiE, representing very closely the Setellse and 

 Antaridae in the general form of the body, the abdomen and its appen- 

 dages, although different in having no posterior antennae. A second, 

 Ergasilhle, having the form of the Corycaeidae, together with their 

 prehensile posterior antennae. A third, the Nicothoid^e, most nearly 

 related to the Harpactici. The large lateral appendages in Nicothoe 

 are independent of its type of structure, and can hardly be more than 

 a subfamily characteristic, separating them from other species that 

 are destitute of these appendages. 



The characteristics of these families and of the genera they com- 

 prise, are as follows : — 



Fam. I. MONSTRILLIDJE. 



Corpus elongatum fere cylindricum. Abdomen 5-6-articulatum, seg- 

 ments lmo et 2do appendicibus setosis munitis ac in Setelld. Max- 

 illae, antennae posticae et pedes antici obsoleti, pedes octo maxime 

 biremes. 



G-. Monstrilla, Dana. 



Fam. II. ERGASILIM:. 



Corpus breviusculum, cephalothorace crasso, abdomine stylis caudalibus 

 minutis setigeris confecto. Antennae posticae subprehensiles ac in 

 Corycceo, pedes octo postici bene biremes. 



G-. Ergasilus, Nbrdmann. 



