62 



THE ENTOMOLOGIST. 



5. C. CALEDONiCA (Kirkalcly) (= cognata of Saunders). From 

 Scotland only ; rare. 



Abctocorisa,* Wallengren (including Basileocorixa, Kirkaldy = 

 Corixa, auctt. = Glcenocorisa, Saunders). 

 This is the largest genus of Corixidae numerically, with 

 eighteen described British species. Arctocorisa was separated 

 from Corixa, auctt. (i. e., Basileocorixa) on a feeble character, 

 viz., the entirety of the pronotal keel, but is unfortunately the 

 oldest available name for the fused genus. The species may be 

 identified as follows, but the males should always be confirmed 

 by my descriptions and figures (' Qiiekett Journal ') of the palae, 

 &c. The pattern and colouring in forms occurring in the peat 

 districts of Scotland and Ireland often become obscure, so that 

 identification of the females is then difficult. The following table 

 is largely adapted from Saunders : — 



1. Corium not rastrate ...... 2. 



1«. Corium rastrate, at least at the base ... 4. 



2. Dark and pale lines on pronotum equally broad . 3. 

 2a. Pronotum pale with narrow dark lines . . . lateralis. 



3. Pronotal keel nearly half as long as pronotum . selccta. 

 3rt. Pronotal keel not more than one-fourth as long as 



pronotum ....... luguhris. 



4. Species not under 7 mill, long .... 5. 



4 a. Species 6 mill, or less 11. 



5. Clavus and corium very rastrate, dull, transverse 



pale lines very narrow, nearly entire . . 6. 



5 a. Clavus and corium not so deeply rastrate, less dull, 



transverse pale lines wider, much abbreviated 



and interrupted ...... 7. 



G. Apex of corium usually widely pale, pronotum 



with seven to eight pale lines .... saJdbergi. 

 6a. Pronotum with six pale lines, apex of corium not 



pale .*........ linnei. 



7. Pronotum with six pale lines .... undid ata. 

 7 a. Pronotum with seven (or more) pale lines . . 8. 



8. Pronotal keel strong, almost entire ... 9. 

 8a. Pronotal keel more or less feeble, not reaching to 



more than half the length of the pronotum . 10. 



9. Yellow beneath ....... germari. 



9 rt. Black beneath, with pale margins . . . . carinata. 



10. Pronotal angles acute ...... striata. 



10a. Pronotal angles obtuse ...... distincta. 



11. Intermediate tibife scarcely longer than the tarsi, 



tarsi and claws subequal ..... mcesta. 

 11a. Intermediate tibiae much longer than tarsi, tarsi 



much shorter than claws ..... 12. 



12. Pronotum not longer than vertex, with five to six 



transverse, pale lines 13. 



* Greek arktos, the north ; Greek basileus, king. 



