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TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



Cercyon littoralis, Gyll. 

 C. depressus, Steph. 

 Heterocerus marginatus, 



Bose. 

 Iuymnaeum nigropiceu m. 



Marsh. 

 C Menus lateralis San . 

 Trechina lapidosus, Daws. 

 Bembeclium continuum, 



Putz. 

 B. ephippium, Marsh. 

 Aepus marinus, Stroem. 

 A. Rohinii, Lab. 

 Mieralymma brevipenne, 



Gyll. 



7 Wogoph lo eus anglicanus , 



Sharp. 

 Myrmecopora (Xemisa) 



uvida, Er. 

 M. sulcata, Kies. 

 Cqt'uis cicatricosus, Er. 

 C. xantholoma, Grav. 



C. se rice us, Holme. 

 C.fucicola, Curtis. 



A ctocharis Readingii. 



Sharp. 

 Phyfosus spinifer Curtis. 

 P. balticus, Kraatz, 

 P. nigriventris, Chev. 

 Diglossa m ersa , Hal. 



D. silmaticollis, Rey. 



DlPTERA. 



A marked feature among marine flies is the reduction 

 or total atrophy of the wings. The first stage in the 

 reduction is seen in Chersodromia arenaria, where the 

 wings are much shortened so as to be of very little service 

 in flight. This is carried a step further in a Southern 

 France species, Psamathiomya pectinata, Derby, in which 

 the wings have become greatly narrowed and strap-like, 

 and the nervures atrophied ; a similar condition is seen 

 in a Calif ornian marine fly, Eretmo ptera Brown i, Kellogg. 

 An extreme case occurs in the females of the genus 

 Clunio, where the wings have disappeared completely, 

 although in the males they are tolerably well developed. 



This reduction of the wings has been explained as 

 being an advantageous condition, since it prevents the 

 insects from being blown out to sea. A similar explana- 



