278 On Fossil Arthropods in the British Museum. 
Formica heteroptera, sp. n. (Formicidae). 
Anterior wing about 13°5 mm. long; submarginal cell 2 mm. 
Marginal cell extremely narrow, formed as in Colobopsis 
stricta. (Jerdon) ; submarginal cell small and narrow ; 
discoidal cell quadrate, higher than long. The following 
measurements are in w#:— Width (depth) of marginal cell 352; 
upper portion of basal nervure 480; lower section of basal 
nervure (which is arched, and not in a straight line with 
upper portion) 960; discoidal cell on submarginal about 560; 
lower end of basal to transverso-medial 1120; greatest 
depth of submarginal cell (at level of end of discoidal) 
about 800. The terminal section of the medius is strongly 
arched. 
Bagshot Beds, Bournemouth (J. S. Gardner). British 
Museum, In. 19033. The reverse is labelled In. 18587, and 
should come from Creech according to the accompanying list, 
but this is evidently an error. 
This is a very singular species, combining the characters 
of Colobopsis and Formica, but in some respects different from 
both. When better known it may prove referable to a 
distinct genus. I do not know the venation of the genus 
Glaphyromyrmex, Wheeler, from Baltic amber. 
Megapterites (gen. nov.) mirabilis, sp. n. (Pseudosiricide). 
(Fig. 3.) 
So far as the anterior wing shows, the genus is similar to 
Formicium, Westwood, but the first marginal cell is much 
Fig. 3. 
Megapterites mirabilis. 
higher than long, much narrowed above, bell-shaped ; the 
anterior and posterior sides of second discoidal cell are not 
nearly parallel; the transverso-medial has its lower end a 
little basad of the upper (compare Teredon) ; the vein M, 
leaves setond discoidal cell near the lower end of its outer 
side, and is distinctly arched, as in many ants. The second 
