ALONA. 131 



than in harpcB; anterior branch has four setae, one spring- 

 ing from the second, and three from the extremity of last 

 joint only. 



Abdomen has a gibbous projection about the middle of 

 the lower margin, and is serrated at extremity. Intestine 

 convoluted, having one turn, and nearly half another. 

 One ovum. 



In size, this species is about the smallest of the family 

 that I have met with. 



Hah. — Pond at Norwood Green ; and near Southall, 

 Middlesex, June 1841. Kare. 



Genus 5 — Alona. 



Lyncetjs, Miiller, et auctomm. 



Alona, Baird, Aim. aud Mag. Nat. Hist., ii ; Trans. Berw. Nat. Club, ii. 



Character. — Shell quadrangular-shaped, grooved or 

 striated longitudinally. Inferior antennae or rami short. 

 Beak blunt, and nearly erect. 



I. Alona quadrangularis. Tab. XVI, fig. 4. 



Lynceus qtjadkangijlaris, Miiller, Zool. Dan. Prod., No. 2393, 1776 ; 



Entomost., t. 9, f. 1-3. 



— Latreille, Hist. Crust., 208. 



— Baird, Trans. Berw. Nat. Club, 100. 



— M. Edicards, Hist. Crust., iii, 388. 



— Koch, Deutscli. Crust., li. xxxvi, t. 15. 

 MoNOCULUs QUADK.ANGULUS, Gmelin, Syst. Nat., 3008, No. 61. 



— Manuel, Enc. metli., viii, 733, t. 268, 



f. 18-20. 

 MoNOCULUS QtiADUANGULARis, Fabricius, Ent. Syst., ii, 498. 

 MoNOCULUS STKiATUS (?), Jimne, Hist. Monoc, t. 16, f. 1, 2. 

 Alona quadrangularis, Baird, Ann. and Mag. Nat. Hist., ii, 92, t.3, 

 f.9-ll,1843;Trans.Berw.Nat.Club,ii,151. 



Nearly quadrangular-shaped. Shell transparent, of a 

 deep-brown colour ; strongly ciliated on anterior margin, 



