8 NEUROPTERA. 



fragment of the existing species. Pictet's beautiful mono- 

 graph is doubtless the best work we possess on the JEphe- 

 meridce, and is certainly a rich source for the investigator. 

 Considering the scanty materials of 54 species which he 

 possessed, we must not complain that the descriptive portion 

 is frequently insufficient, especially since of 28 species he 

 only had before him one condition. 



With respect to the English authors, I do not precisely 

 know what occurs in the older authors, such as Berkenhout, 

 Samouelle, Donovan ; but, as far as I remember, it is unim- 

 portant. Leach, in the Edinburgh Encyclopaedia, 1815, 

 t. ix. p. 1, p. 127, divides these insects into two famihes, 

 Baetidce and Ephemeridce, with two and three caudal fila- 

 ments. The former contains two genera, Baetis (bioculatus) 

 with four, and Cloeon (pallida) with two wings; the latter 

 one genus, Ephemera (vulgata). 



Curtis, Philos. Magazine, 1834, vol. 4, p. 120, describes 

 very briefly nineteen species ; 1 Ephemera^ 11 Ba'etis, 4 

 CIoeoHj 3 Brachijcerus. The last-named genus is synony- 

 mous with Ccenis of Stephens. In the second edition of the 

 Guide (1837) he enumerates fifty-six species, viz. 17 EpJie- 

 mera, 7 Brachycerus^ 22 Baetis, 10 Cloeon. In his British 

 Entomology he figures Ephemera cognata and Baetis dispar 

 in his usual masterly style. The types I have not examined. 



Stephens describes (1835), Illustrations, Mandibulata, 

 vol. 6, p. bOy the fifty species already enumerated in his 

 Catalogue, and figures three of them. His descriptions are 

 very short and unsatisfactory, and, as he observes at p. 62, 

 some of the insects were much injured by damp. The 

 Curtisian types were not compared by him, and six species 

 were only taken from the Curtisian descriptions. Of the 

 sixteen species placed in the genus Ephemera, only the two 

 first belong thereto, the remainder to Potamanthus, some 



