LYNCEID;E. 117 



ination till Milne Edwards published his work on the 

 Crustacea in 1840.* In this work the author shows 

 the necessity for breaking down this heterogeneous genus, 

 and reforming it ; but he does not make the attempt 

 himself, nor do I know of any attempt having been made 

 before I published my paper on the Lynceus, in the 

 ' Annals and Magazine of Natural History/ 



Anatomy and Physiology^ Sfc. In general formation 

 the animals of this family are very much like the 

 Daphniadae; the most remarkable points of difference 

 being the shape of the head and beak, and a small black 

 spot a little distance from the eye, much smaller than it, 

 which is considered by Miiller as a second organ of vision, 

 and from which he has given the name to the genus. f 

 The shell or covering which incloses the body does not 

 consist of two distinct and separate valves, but is open 

 only on the anterior margin, and for a portion of the 

 posterior extremity. The part which we may call the 

 head is harder than the other portion of the shell, and is 

 prolonged in most of the species into a sharp and very 

 distinct beak. Belonging to it we find, besides the beak, 

 the eye with its accompanying black spot, the superior 

 antenna, the inferior, or rami, the brain, mouth, and 

 part of the digestive canal. 



The eye (t. XV, f. 1 /), as in the Daphniadse, is a 

 spherical body contained in a somewhat funnel-shaped 

 sheath of muscles, having a semirotatory motion, and 

 consisting of a series of crystalline bodies ; which, in the 

 Eurycercus lameUatus, are about twenty in number. 



The black spot, which Miiller considers as a second eye, 

 is situate before, and at a little distance from, the real 

 eye, generally near the end of the beak, almost at the 

 extremity of the body of the animal, and near the root 

 of the antennae. It is much smaller than the eye, has no 



* Hist. Nat. des Crust., vol. iii. 



f "Nomeu Lyncei in Zool, Dan. prod, ex punctis binis ocellaribus, qua;, 

 organa visas absque d'ubio sunt, indixi." Eutomost., p. 67. 



