1358 The Zoologist— September. 1868. 



From these instances we gather the following conclusions: — 



1st. That in limited districts, such as Britain, species — as the wolf — 

 formerly abundant have been entirely exterminated ; that in districts 

 less limited, as Europe, the number of individuals constituting a 

 species — as the aurochs — is rapidly diminishing. 



2nd. That within the historic period large species — as the dodo — 

 have been utterly exterminated, swept from the face of the earth, and 

 that others — as the cassowary — are now tottering over their graves. 



3rd. That man, generally the Caucasian, especially the Anglo- 

 Saxon, has been the great agent in this destruction. 



Edward Newman. 

 (To be continued.) 



On the Habits of a Tipulideous Larva. By Edw. D. Cope. 



(From tlie ' Proceedings of tlie Academy of Natural Sciences of Philadelphia,' 



18G7, p. 222.) 



There has been known in Europe for many years a small white 

 larva, which is called the army worm, which gathers itself into large 

 bodies forming streams of several feet in length. These bodies move 

 forward at a slow rate, and appear to be a form of migration which the 

 species adopts for some purpose unknown. Their superficial 

 resemblance to a sluggish serpent usually excites repugnance in the 

 minds of many observers. It has been found that these larvae are 

 those of different species of the flies of the genus Sciara, which belongs 

 to the Mycetophilidas, which was formerly regarded as a group of the 

 great family Tipulidae, or the crane-flies. 



Of this genus Osten Sacken* says: — "All the larvoe of the 

 Mycetophilidas are gregarious, and live among decaying vegetable 

 matters. * * Sciara is found among decaying leaves in vegetable 

 mould, in cow-dung, under the bark of dead trees, &c. * * They 

 may be distinguished from the larvae of Mycelophila by their greater 

 delicacy, and by the structure of the tropin ; most of them seem to 

 have no bristles or spines on the locomotive processes on the under 

 side of the body, whereas the majority of the Mycetophilae have them. 



* Who has described the larrffi, aud given the bibliography of the European 

 species (Proc. Entom. Soc. Phila. 1854, pp. 163 — 170). I am indebted to this 

 excellent entomologist for the identification of larva; from Westtowu, sent him, and 

 for reference to the above essay. 



