49 



In the present state of knowledge the following table may 

 suffice to discriminate the genera of this family : — 



Second pair of trunk-legs wanting. 



1. Paracrangon, Dana, 1852. 

 Second pair of trunk-legs present, 2. 



( Second pair of trunk-legs simple. 2. SabineayO'WQny 1835. 

 \ Second pair of trunk-legs chelate, 3. 



Fourth and fifth pairs of trunk-legs, seventh joint laminar. 



3. .//-^vi, Kroyer, 1843. 

 Fourth and fifth pairs of trunk-legs, seventh joint not 

 laminar, 4. 



( Second trunk-legs subequal in length to the rest, 5. 

 I Second trunk-legs much shorter than the rest, 6. 



[ Body dorsally little or not at all sculptured. 



\ 4. CniJigon, Fabricius, 1798. 



i Body dorsally strongly sculptured. 



\ 5. Scleroci'angon, Sars, 1882. 



( With only five pairs of branchiae. 6. Philochcras^ n.n. 

 I With more than five pairs of branchiae, 7. 



Apices of branchiae turned backward. 



7. Pontdpiiilus, Leach, 1817. 

 Apices of branchiae turned forward. 



8. y^geoii, Guerin-Meneville, 1835. 



Gen. : ^F)GEON, Guerin-Meneville. 



1816. Egcon, Risso, Hist. Nat. Crust, de Nice, p. 99. 



1825. Egeon (part), Desmarest, Consid. gen. Crust., p. 218. 



1826. Egeon, Risso, Hist. Nat. Europe merid., vol. 5, p. 64. 

 1835. yEgcon, Guerin-Meneville, Exp. Sci. Moree. 



1837. Crangon (part), Milne-Edwards, Hist. Nat. Crust., 

 vol. 2, p. 340. 



1862. ^geon, Kinahan, Proc. Roy. Irish Acad., vol. 8, 



part I, p. 9. 



1863. Crangon (part), Heller, Crust. Siidl. Europa, p. 224. 



1 88 1. Crangon {Cheraphilus), Miers, Ann. Nat. Hist., Ser. 5, 



vol. 8, p. 365. 

 1885. yEgeon, Carus, Prodr. Faunae Mediterraneae, vol. i, 



p. 483. 

 1888. Pontocan's, Bate, Challenger Macrura, Reports, vol. 



24, P- 495- 

 1890. uEgeon, Ortmann, Zool. Jahrb., vol. 5, part i, p. 530. 

 1893. Egeon, Stebbing, Hist. Crust., Intern. Sci. Ser., 



vol. 74, p. 226. 



