308 BEITISH LEPIDOPTERA. 



concolorous ; posterior wings and fringes of the same tint as the 

 anterior wings. 



Sexual dimorphism. — Male : Ample winged, and the largest of the 

 Fumeids occurring in Britain. Its colour varies from deep brown to 

 fuscous (and more rarely to grey-fuscous) ; antennal joints 21-24 

 (usually 24) ; tibial spur eleven -sixteenths of length of tibia. Bruand 

 describes the male as being of an intense brown and very shining, the 

 antennae pectinated, the wings oblong in shape, appearing distinctly 

 larger than B. comitella which has almost exactly the same measure- 

 ments but with the wings more elongated and narrow. Female: 

 Bruand describes the female as araneiform, entirely apterous, short, 

 bent in a semicircle ; the anterior portion slender, the head very small, 

 corneous and shining ; the body (which appears slightly silky) is of a 

 vinous tint, with six blackish-brown rectangular chevrons occupying 

 the dorsal area, commencing on the 1st abdominal segment ; a blackish 

 corneous shield is present on the dorsum of the three thoracic segments 

 which are very contracted ; the legs are long ; the anal area is terminated 

 very obtusely by a large tuft of downy hairs (whitish-grey above and 

 brown below), in which the ovipositor is placed. The feet are horn- 

 colour ; the antennas short ; short and exceedingly fine silky hairs may 

 be observed all over the body ; ventrally there is a blackish spot 

 at each incision. Our own description of a female, bred from a case 

 found at Bournemouth, is as follows : Of a dark flesh colour (" slightly 

 vinous," Bruand), the antennas black on either side of thorax, the 

 head and legs black-brown and shiny, the latter with pale terminal 

 hooks ; the pro- and mesothorax covered with a shiny, black-brown, 

 corneous plate ; the head, pro-, meso-, and metathorax smaller than 

 the 1st abdominal which swells suddenly at about its centre, the other 

 abdominal segments being swollen and distended ; a large, transverse, 

 corneous, dark brown shield covers the anterior half of (?the metathorax, 

 and) the first six abdominal segments dorsally, that on the 6th being 

 more solid, not centrally divided ; those on the preceding segments 

 divided by a longitudinal medio-dorsal line (? depression) ; these plates 

 only extend on either side to the subdorsal area although the subseg- 

 ments on which the plates are placed (and of which they are the dorsal 

 parts), are sharply cut off laterally and ventrally from the subsegment 

 following ; the whole of the abdominal segments behind the 6th are 

 much modified, a ring of dirty whitish or yellowish silky hairs surround- 

 ing the posterior edge of the 7th abdominal, the 8th- 10th being modified 

 into the ovipositor ; hairs are distinctly visible on the sides of the 

 abdominal segments (Described June 7th, 1899, from moth reared 

 from larva sent by Mrs. Cowl). Chapman notes the ? as having 

 diminished tarsal joints, usually 3, 4, 4, for the three legs, but 

 occasionally with 3, 3, 4 and 4, 4, 4, so that there is obviously con- 

 siderable variation in this direction. 



M. crassiorella as a British species. — This species was first 

 introduced as British by Bond in 1867, and confirmed by Knaggs in 

 1867, and Mitford in 1869. In introducing (JEnt. Mo. May., iv., p. 113) 

 it as British, Bond writes: "The males are larger than either F. 

 nitidella or F. roboricolella, to which group they belong. The ? is 

 larger and more obese. I have had males in my cabinet for some time, 

 but it was only by breeding the female this year that I was enabled to 

 make out the species. There are good figures in Bruand's Monograph, 



