ALONA. 131 



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

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

 joint only. 



Abdomen has a gibbons 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. 



Halt. Pond at Norwood Green ; and near Sonthall, 

 Middlesex, June 1841. Rare. 



Genus 5 ALONA. 



LYNCETJS, Midler, et auctomm. 



ALONA, Baird, Ann. 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. 



1. ALONA QUADEANGULARIS. Tab. XVI, fig. 4. 



LYNCEUS QUADRANGTJLARIS, Midler, Zool. Dan. Prod., No. 2393, 1776 ; 



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

 Latreille, Hist. Crust., 208. 

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

 M. Edwards, Hist. Crust., iii, 388. 

 Koch, Deutsch. Crust., h. xxxvi, t. 15. 

 MONOCTJLTJS QUADRANGULUS, Gmeliii, Syst. Nat., 3008, No. 61. 



Manuel, Enc. meth., viii, 733, t. 268, 



f. 18-20. 



MONOCTJLUS QTJADRANGTJLARIS, Fabricius, Ent. Syst., ii, 498. 

 MONOCULUS STRIATTJS (?), Jurine, Hist. Monoc., t. 16, f. 1, 2. 

 ALONA QUADUANGULABIS, 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, 



