fie 
48 
FOOD AS INFLUENCING VA VARIATION IN HELICES. 
JOHN HAWK = oes NS, 
For the past four seasons I have i. ciade a few notes respecting 
the forms and colours of Snails feeding on various plants. 
I find that the Black Horehound (allota nigra) generally 
produces the Helix nemoralis and H. hortensis of a very dark 
rown or nearly blac 
e Epilobtum isan or Great Willow-Herb produces 
the same shells very large and of a beautiful yellow colour. 
ave always found the best examples of var. /:lacina 
feeding on the Ground Ivy (Nepeta glechoma), while Jack-by- 
the-Hedge (Szsymbrium alliarza) nearly always produces very 
fine var. rubella. 
The Common Blackthorn (Prunus spinosa) seems to be the 
favourite food-plant for the var. castanea of H. hortensts, and 
the same may be said of var. hyalosonata and the Pastinaca 
sativa. 
The Common Nettle (Uréca sp.) supplies most of the five- 
banded varieties, and on the Coltsfoot or Cleat (Zusszlago 
Jarfara) | found 32 white examples out of 46 A. nemoralis. 
e Ash (Fraxinus excelsior) supplies food for H. seen 
and H. hortensis, which are principally of pale colour 
When at Castle Howard last summer I noticed a large bed 
of Knapweed cee nigra) which had n all its 
foliage eaten off by a white variety of Helzx virgata, and 
a short distance off the same Snail was feeding on the Plantage, 
and were nearly all very darkly banded. 
I also found that the Helzx aspersa fed on the Burdock 
(Arctium lappa) are much lighter in colour than those fed on the 
Heracleum spondylium, while some which feed on the Common 
Ivy (Hedera helix) are quite a bright red colour. 
he Common Vetch (Vrcta sativa) seems to produce the 
minor varieties. I have seldom found A. hortensis on this plant 
larger than 17. virgata. 
PRESIDE Pin ce eReA RTE 
NOTE—ORTHOPTERA. 
Periplaneta aeeparniage at sid rn ral months ago, Mr. S. L. 
Mosley showed me rie mens of this * Cackroash which had been 
sent to him by s BL allidaye and bee =n found in considerable num- 
bers ina Dehaene at S ibden, Halifax. It is only a few years since the 
species was first noticed in Britain, and like our other representatives of t 
genus, — d through importation, but it s to be spreading 
Bag 
hin the country, though this, I believe, is its first observed occurrence in 
north.—GEo. T. poner Crosland Hall, Huddersfield, 18th Jane ee 
