CALIGUS. 269 



Genus 1 — Caligus. 



Caligus, Miiller, Eutomostraca. 



— Latreille, Cuvier, Lamarck, Leach, Desmarest, Nordmann, 



M. Edwards, Pickering and Dana, Kroyer, 8)-c. 

 MoNOCULUS, Linnaus, Fahricius, Manuel. 

 BiNOCULUS, 0. Fahricius, Faun. Green. 



— Midler, Zool. Dan. Prod. 

 Pediculus, Busier, Opusc. Subseciv. 



— Strom, Phys. og Oeconom. Besk. 

 Oniscus, Slabber. 



Character. — Fourth pair of feet slender, of only one 

 branch, and serving the insect for walking. Thorax ex- 

 hibiting only two distinct articulations. Frontal plates 

 possessing a small sucking-disc or lunule on the under 

 surface of each lateral portion. 



1. Caligus diaphanus. Tab. XXXII, fig. 1. 



Caligus diaphanus, Nordmann, Microgr. Beitr., ii, 26. 



— Kroi/er, Tidsskrift, i, 623, t. 6, f. 5. 



— 3L Edwards, Hist. Nat. Crust., iii, 452, No. 5, 



— Thompson, Ann. Nat. Hist., xx, 247. 



— Buster, Op. Subsec, ii, t. 8, f, 9 b (?). 



Description. — Male. Carapace large, and nearly round; 

 frontal plate of considerable size ; lunules distinct but 

 not large. Antennae of moderate size ; basal joint large, 

 and setiferous on external edge. Thorax very much 

 smaller than carapace. Penultimate segment very small 

 and narrow ; the last somewhat lunulate, the external 

 posterior angles terminating in a projecting lobe, which 

 is shortly bifurcated, the external fork giving off one, 

 and the internal two, short plumose setae. 



Abdomen nearly as long, but narrower than the last 

 joint of thorax, and terminating in two pretty large caudal 



