ORDER PCECILOPODA. 375 



Cecrops, Leach, 



Of which but a single species is known, which has been found* 

 attached to the gills of the tunny and the turbot, the Cecrops 

 de Latreille (Leach, Encyc. Brit. Suppl. i. pi. xx. 1. 3, male, 

 — 2, 4, female— 5, antennae, magnified. Desm. Consid. 1. 2.) 

 The second tribe, that of Lern^eiformes, Lat., is com- 

 posed of entomostraca still more approximated than the pre- 

 ceding, from their external forms, to the lerneae. The number 

 of discernible feet is but ten, and these organs are for the most 

 part very short, and not at all, or but little, adapted for swim- 

 ming. Sometimes the body is almost vermiform, cylindri- 

 cal, with the anterior segment simply a little broader, and 

 provided with two advanced didactylous forceps ; sometimes, 

 in consequence of two lateral expansions in the form of lobes, 

 or wings, thrown behind the thorax, and of the two posterior 

 ovaries, it forms a small quadrilobate mass. This tribe is 

 composed of two genera. The first, that of 



DiCHELESTiUM, Hermann (Son), 



Presents us with a naiTow and elongated body, a little dilated 

 in front, composed of seven segments, the anterior of ^vhich 

 {corslet, Hermann), is broader, rhomboidal, formed of the head, 

 and a portion of the thorax united. It supports, 1st, four 

 short antennae, the lateral of which are filiform, and composed 

 of seven articulations, and the intermediate advanced in the 

 manner of little arms, of four articulations, with the last in 

 the form of a didactylous forceps; 2nd, a siphon, inferior, 

 membranaceous, and tubular; 3d, three sorts of shapeless 

 palpi (two multifid feet ?) on each side, situated on a promi- 

 nence ; 4th, four feet adapted for seizing, of which the first 

 two are formed of a thigh and leg, and terminated by divers 

 unequal and denticulated hooks, and the second consist of an 



