CHIROCEPHALUS. 
39 
and not divided into two plates. No appendages at the 
base of cephalic horns. 
1 — Chirocephalus.* 
Chirocephalus, Prevost, 1803 ; Thompson. 
Branchipus, M. Fdivards, Fischer , Latreille , Desmarest, Guerin, Lamarck. 
Ino, Schrank, 1803 ; Oken. 
Cancer, Shaw. 
Character . — Abdomen large, consisting of nine di- 
visions, and terminated by two well-developed caudal 
plates or lamellar appendages ; cephalic horns, of a cylin- 
drical shape, and furnished with fan-shaped and digitiform 
appendages in the male. 
Bibliographical History . — A figure of the Chirocephalus 
was given by Petiver, in his * Gazophylacion Naturae,’ as 
early as 1709. He mentions it as a native of England, 
but merely describes it shortly, as “ Squilla lacustris 
minima, dorso natante.” It was afterwards described at 
greater length, as British, by Edward King, e.r.s., who 
read, before the Royal Society, a short description of “ a 
very remarkable aquatic insect, found in a ditch of stand- 
ing water, near Norwich, in the spring of the year 1762,” 
and which is published in the c Philos. Trans/ for 1767. 
“ They were discovered,” he says, “ by a poor man now 
dead, whose genius was very extraordinary, and much 
superior to what is usually found in his rank. He was 
indefatigable in his searches after everything curious, and 
without ever having had any advantages of education, 
had acquired a degree of knowledge by no means con- 
temptible. ... In the ditch from which they were taken,” 
he continues, “ there were a vast multitude of the same 
kind, though they have not been found in any other place 
that I know of. From their being prolific in this state, 
* From x u P , a hand ; and KttyaXov, head. 
