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JOURNAL OF VARIATION. 



Vol, XXV. No. 1. 



January 15th, 1913. 



Some Notes on the Genus Myrmica, Latr. 



(Witli one plate and several figures.) 

 ByH. St. J. K. DONISTHORPE, F.E.S., F.Z.S. 



The type of the genus Mijrnnea, Latreille^ is, as pointed out by 

 Wheeler,'- the Formica riifa, L. Emery-^ considers the F. rubra, L., to 

 include both .17. laevinodis, Nyl., and J/. ruiiinocUs, Nyl., in which he is 

 no doubt correct. It is impossible to say which of the two Linnaeus* 

 really meant, so the name rubra must be dropped. 



In Myrmica the antennae are thirteen jointed in the male, and 

 twelve jointed in the female and worker. There are two nodes to the 

 pedicle, the petioleand post-petiole; the ? and ^ are armed with a sting, 

 and no ocelli are present in the latter. The larvae never spin cocoons, 

 the pupte being always naked. 



The following characters will separate Myrmica from all our other 

 genera in the Myrmicinae: — 



Mandibles broad, three cornered, and toothed on the inner side ; 

 petiole rounded, post-petiole not armed with a spine beneath ; club of 

 antennae more than two jointed ; epinotum armed with spines ; eyes 

 large, prominent; three last joints of the funiculus of the antennae 

 together much shorter than the rest. The forewings with one sub- 

 marginal cell divided by a transverse nerve which enters the cell and 

 half divides it. 



Typical Mtkmica wing, 

 fokewing of m. ruginodis (j 



1 Hist. Nat. Crust, et Insect, iv., 1802, p. 131. 

 - Ann. New York Acad. Science, xxi., 1911, p. 168. 

 3 Deutsch. Ent. Zeitschr., 1908, p. 169. 

 * Stjst. Nat., ed. x., 1758, p. 580. 



