MALACOSOMA. 



529 



americana at the "trap lanterns " of the Cornell Agricultural Experi- 

 ment Station, between June 17th and July 18th, 1889, whilst Dyar 

 notes {Psyche, 1891, p. 126) the capture of 2416 specimens of the 

 same species, in five visits, paid between June 14th and July 9th, 1891, 

 to the electric light globes at Poughkeepsie, N.Y. Standfuss observes 

 (Handbuch, &c, p. 119) that M. castrensis, M. neustria, and M.franconica 

 each lay from 400-600 eggs. He further notes that in 1884 he reared 

 405 examples of 21. castrensis, of which 207 were males, and 198 

 females. When the latter species was abundant on the Essex marshes 

 in 1896, Whittle bred a large number, the females being as 3^ : 1 

 compared with the males. Of 70 bred in 1890, the females out- 

 numbered the males by more than four to one. 



Our two British species have an almost Palrearctic distribution, M. 

 castrensis extending into central Asia and Amurland, whilst 21 . neustria, 

 in a form scarcely distinguishable from our own examples, abounds in 

 Japan and China, and the slight modifications that it has undergone 

 in North America, afford excellent material for study ; yet the distribu- 

 tion of both these species within the limits of the British Islands is at 

 present totally inexplicable. Why 21. castrensis, that extends well into 

 Scandinavia and Finland, should be restricted in Britain to the flooded 

 marshes around the mouths of the Thames and Medway, where it is in 

 amazing abundance in some seasons, is quite incomprehensible, nor does 

 Chapman's explanation (Ent. Rec, xi., p. 62) that it appears to 

 require flooded areas, help us much when we consider its habitats in 

 other parts of its range. Still more remarkable is the sudden failure 

 of 21. neustria in our northern English counties, and its entire absence 

 in Scotland, for it swarms in countless numbers in many seasons 

 in certain places in the counties which practically form its northern 

 limits — Carnarvon, Denbigh, Leicester and Lincoln. These are matters 

 that still require to be elucidated by the British lepidopterist. 



The genus Malacosoma is essentially Palsearctic and Nearctic. The 

 only species outside these areas would appear to be indica from the 

 East Indies, and bilineata (doubtfully a Malacosoma) from Senegambia. 

 The following list of species in the genus has been taken from the 

 works of Kirby and Dyar : 



M. alpicola, Staud. 



. Alps of C. Europe. 



M. ? fiavomarginata, Pouj. 



. Mou-Pin. 



M. castrensis, Linn. 



Europe, N. and W. Asia. 



M. intermedia, Mill. 



South France. 



M. franeonica, Esp. 



S. Europe and W. Asia. 



M. neustria, Linn. 



. Europe to Japan. 



M. testacea, Motsch. 



. Japan. 



M. luteus, Oberth. 



. Algeria. 



M. indica, Walk 



East Indies. 



M. americana, Fab. 



. Florida to Canada. 



M. fragilis, Stretch 



Rockies — Central arid region 





of Colorado. 



M. pluvialis, Dyar 



. The Pacific North-west. 



M. ambisimilis, Dyar 



California and Colorado. 



M. californica, Pack. 



California (coast). 



M. constricta, Stretch 



California (hills). 



M. strigosa, Stretch 



Yosemite Valley. 



M. erosa, Stretch 



The Pacific North-west. 



M. thoracica, Stretch 



California and Colorada. 



M. incurva, H.-Edw. 



Arizona. 



M. disstria, Hb 



Mississippi valley to Atlantic. 



M. mus, Neum. 



. S.-W. Utah, Mexico. 



