CERURA BICUSPIS IN HEREFORDSHIRE. 75 



placed her on a tree trunk in the garden at full liberty, at dusk. A 

 couple of hours later I found her in cop., and she afterwards laid six 

 or seven dozen fertile eggs, those first laid being, as I suspected, 

 infertile. 



The most remarkable circumstance about C. bicusjiis in Hereford- 

 shire is its distribution. It occurs over the whole county except the 

 north-eastern portion — that which for entomological purposes I call 

 " Wood's country," This portion, including the Woolhope Valley and 

 Valley of the Frome, possesses Silurian and earlier rocks, and a richer 

 and more varied fauna and flora than the rest of the county, which is 

 a monotonous stretch of Old Red Sandstone. My friend Dr. Wood 

 finds this district wonderfully rich, especially in micros, and it is cer- 

 tain that did C. bicnspis occur there, it had often fallen to his net and 

 pin. It is presumptuous of me to say so, as such confirmation is 

 very superfluous, but I have also looked for it in that portion of the 

 county, in very suitable-looking spots, without seeing a trace. In the 

 rest of the county it occurs all along the Wye Valley, in the Valleys of 

 the Lugg and Monnow and their tributaries. Its head quarters are 

 assumed to be at Dinmore, where birch grows in large quantities ; yet 

 it is harder to find an empty cocoon there than anywhere else, and I 

 have only once found a full one there. It also occurs in all parts of the 

 upper Wye Valley, in Breconshire and Radnor, that I have examined, 

 at Three Cocks, Builth, Rhayader, Llandrindod, etc. Alder is still so 

 abundant in some of these districts, that the insect must be much 

 more abundant than in Herefordshire. 



As to the comparative abundance of C. licuspis at Tilgate and in 

 Herefordshire, I rarely meet with so many as a dozen empty cocoons 

 in a day's (i.e., an hour or two) search, whereas I hear of 80 or 40 

 being seen in Tilgate in a day. On the other hand, on the only occa- 

 sion on which I visited Tilgate, I could not see a trace of C. hicnspis, 

 in a search which would probably have disclosed several empty cocoons 

 in similar country in Herefordshire. 



On the Interbreeding of Spilosoma mendica and its var. rustica. 



By J. W. TUTT, F.E.S. 



With the addition to the British fauna of the dark varieties of 

 Spilosortia menthastri, which were obtained in Argyllshire and Elgin 

 last year, followed by the successful breeding of the same forms during 

 the present season by various collectors, a healthy interest in this 

 genus has again naturally manifested itself among British entomolo- 

 gists. 



The fact that these dark S. menthastri have assumed more or less 

 the smoky tint which normally characterises the male of S. mendica, 

 leads me to refer to another paper by Mons. 'A. Caradja, whom I 

 quoted so largely in my "Notes on the Variation of Spilosoma mendica " 

 {Ent. liec, vol. v., pp. 185—189). 



In Societas Entomologica (vol. x.. No. 7, July 1st, 1895) Mons. 

 Caradja gives further details of the results of crossing S. mendica var. 

 rustica with the type form. It would appear that the male of 

 var. rustica, as obtained in Roumania by Mons. Caradja, is somewhat 

 whiter than the Irish form which we knoAV by that name, being in 

 fact more of the tint of the normal female. The writer, referring to 



