MASONIA CRASSIOEELLA. 809 



pi. ii., fig. 68, a $ , b ? ." In recent years it has been taken by 

 Digby (probably in Dorsetshire), and, in May, 1899, Mrs. Cowl sent 

 larvas from Bournemouth, which produced females, one of which paired 

 with a male (from a Locarno case) bred by Chapman. The latter 

 observer notes that the Bournemouth 5 s presented the special 

 characters of M. crassiorella, and that the Locarno $ that paired Avith the 

 Bournemouth ? refused to look at a ? F. casta. At the time, Chapman 

 says, he did not observe that this ? was M. crassiorella, but later exami- 

 nation showed it to agree with Locarno ? s and to differ absolutely from 

 F. casta. Among Mason's material (mixed with F. intermediella) a 2 

 M . crassiorella was found whose tarsal formula is 3, 3, 8^, the ^ repre- 

 senting an incomplete anchylosis. 



Note on M. crassiorella from various localities. —M. crassiorella 

 is large, certainly always larger than the average of other British forms 

 (or species), although some large northern forms of F. scotica are larger 

 than some M. crassiorella. Comparing M. crassiorella reared from Cannes 

 and Locarno, males sent from Staudinger, and another continental 

 source, five others (British) from Dr. Mason's collection, and a Dorset- 

 shire example from Mr. Digby, one observes that these specimens 

 differ in tone, the bred ones being much darker than the others 

 (whether really or from freshness one is unable to say) ; there is some 

 little difference in wing form, some appearing narrower than others, 

 probably more due to differences of setting, damage to fringes, &c, 

 than to actual fact. The Cannes and Locarno specimens and that 

 from Staudinger differ most, perhaps, in superficial aspect (chiefly 

 colour and setting) but agree absolutely in having 24 joints to the 

 antenna and similar tibial spurs ; the other continental specimens have 

 22-23 joints, whilst the only two of Dr. Mason's whose antennas are 

 sufficiently perfect to count, have respectively 22 and 21 joints, that 

 from Digby has also 22 joints. A male M. affinis from Staudinger has 

 24 antennal joints, a tibial spur of -70 of length of tibia, is a little 

 smaller than M. crassiorella and appears to be more densely scaled ; this 

 appears to be a local form of M. crassiorella, although without further 

 material the opinion is perhaps of little value. [Other continental 

 specimens sent as ill. affinis have 19 joints to antennas, anterior tibial 

 spurs if in length and belong clearly to the casta group] . I am not sure 

 that I have not now two species confounded under this name. The type 

 should be a large species, at least 16mm. in expanse, and those specimens 

 that I regard as absolutely agreeing with this supposed type have 24 

 joints to the antennas and a tibial spur formula of •§Q- , 10. This form 

 I have reared from Cannes and received from Staudinger. From 

 another German source, however, I have received specimens with 22 

 joints to the antennas, and the British specimens I have seen (Mr. 

 Digby's and those in Dr. Mason's collection) agree in this. I have 

 also specimens bred from Locarno larvae with only 22 antennal joints, 

 and a wing expanse down to 12mm. All these have fairly uniform 

 tibial spurs, varying, however, from -64--68 (for British examples), 

 •66- # 69 (the typical 24-jointed form), and •69- , 72 (the Locarno form). I 

 am unable to bring other characters into line with these variations and 

 the number of antennal joints does not vary in accord with the tibial 

 spur. (It is quite possible that my extreme measurements may be 

 somewhat in error and that -QT-'IO is the correct tibial formula for 

 crassiorella) (Chapman) . 



