(. xxi )) 
Microdon, taken in a nest of Formica fusca at Porlock last 
month. A number of larve were taken, and one of the nests 
in which they occurred. The ants are stated to nurse the 
larve as they do their scale insects (Coccidz). 
The PresIpENT warmly congratulated Mr. Donisthorpe upon 
the nature and extent of his discoveries of species of insects, 
etc., attendant on ants. 
HEMIMERUS TALPOIDES, WALK.—Mr. R. SHELFORD exhibited 
a specimen of the curious Orthopterous insect Hemimerus 
talpoides, Walk., from Portuguese Guinea; the species is 
parasitic on a large rat, Cricetomys gambianus, and is 
viviparous. 
Mr. R. SHetrorp then read the following note on 
“ A Case or Homaotic VARIATION IN A CocKROACH.” 
Homeeosis has been defined as “‘theassumption by one member 
of a Meristic series, of the form or characters proper to other 
Left maxilla, Right mazilla, Right mandible. 
members of the series” (Bateson, “ Materials for the Study of 
Variation,” London, 1894, p. 84). This type of abnormality 
is of rare occurrence ; Mr. Bateson is only able to quote four 
examples of it amongst the Insecta, and two of these are 
doubtfully genuine. The undoubted cases are Cimbex axillaris 
and Bombus variabilis, both insects having the left antenna 
partially developed as a foot (Zc. pp. 146-148). I daresay 
that other cases of homeosis amongst insects have been 
recorded during the past twelve years, but if so, I have not 
PROC. ENT. SOC. LOND., 11. 1907, Cc 
