Esbeii Petersen. — Norg'es arktislce Neurnpterfaiina. 151 



ben Petersen, Silkeborg ; Finland (locality and date of 

 Capture not entered on label) 1 $ im. (A ro) in fluid, the 

 genitalia of which, detached and mounted by me in Ca- 

 nada Balsam without compression, are here figured. On 

 comparison of the figures, with the corresponding details 

 of B. excrucians, Walsh [cf. Needham , Mayflies and 

 Midges of New York, N. Y. State Mus. Bullet. 86, 

 Entomology 23, pi. X., fig. 8 (1905)] some resemblance is 

 recognisable in the penes of the two species ; but the for- 

 ceps differ. E. excrucians has no dilatation at the end of 

 the longest joint of the forceps limbs : the omission of the 

 minute hairs or granulations that exist along the inner si- 

 des of the limbs, in the figure concerning E, Aronii, was 

 deliberate. 



The mierometrical scale of enlargment shown in the 

 block-figure was noted down from stage-micrometers diffe- 

 ring from each other in thickness and not exactly in fo- 

 cus with the objects : the camera lucida employed was a 

 Schrikler's Prism-Eyepiece. 15. XI. 1908. A. E. Eaton. 



6. Baëtis b in oc 7t la tus L. 

 Linné, Syst. Nat. 



Om denne Art siger AV. M. Schøyen, at den er al- 

 raindehg i Norge op til Sydvaranger. W a 1 1 e n g r e n an- 

 fører den ogsaa fra Sydvaranger (S c h o y e n). 



7. Baëtis v emits Curt. 



Curtis, Phil. Mag. 



W al len gr en og AV. M. Sc li øy en anfører begge 

 Arten fra Hammerfest og Alten (efter E a t o n). C h a p- 

 raai> har taget Arten paa de samme Lokaliteter, 



