Hairs of certain Lepidopterous Laroic. 



37:j 



refers to tlic larva of Acronycta alni as " mucli roseinbliii:^ 

 both In colour and in its clavate hairs the larva of Tinolius,^^ 

 the latter being figured on pi. xi.; tlie large, strong, clavate 

 hairs of this form, Tinolius ehurneiguttaj Walker, which is a 

 scmiloojK-r, and from its black colour a very conspicuous 

 animal, are represented as being from one fourth to one third 

 as long as the body and are situated on the first two or three 

 segments of the abdomen, this being the most prominent part, 

 forming the loop when the creature is in motion. These are 

 the only cases known to me of the occurrence of flattened hairs, 

 with the exception of the case described by Burmcister and 

 quoted below. 



Scale-like Seta;. — In examining the median dorsal tufts on 

 the second and third thoracic seg- 

 ments of the European Gastropaclia 

 quercifolia I found that they are com- 

 posed of broad lanceolate-oval scales*, 

 whicli are opaque and dark steel- 

 purple in colour, with the surface 

 quite regularly striated, though not 

 invariably so, while the stride do not 

 appear to extend to either end. They 

 vary in shape and in size, some 

 being narrow and with a simple 

 point at the distal end, while the 

 majority are variously notched or 

 toothed. They thus a])pear to be 

 true scales, like those on the wings 

 of adult Lepidoptera. 



In Gastropaclia americana the scales forming the dorsal 

 tufts, both on the two hinder thoracic segments and on the 

 eighth abdominal one, are very different from those of the 

 European species ; they are dark and opaque, but are long, 

 narrow, and flat, very gradually increasing in width to tlie 

 end, which has a single notch. From this notch an impressed 

 line or stria extends along the middle of the scale for some 

 distance. 



Setai flattened at the end. — In Gastropaclia quercifolia the 

 lateral tufts along the body each contain a few long hairs with 

 flattened ends, varying in shape from oval to triangular, with 

 the ends often very broad and ragged, bearing from one to 



Scales from the dor.sal 

 thoracic tufts of Gas- 

 tropaclia quercifolia. 



* These scales were briefly referred to in my article entitled "Hints on 

 the Evolution of the Bristles, Spines, and Tubercles of certain Cater- 

 pillars," Proc. Bost. Soc. Nat. Hist. xxiv. p. 512, 189 (1890). 



Ann. (X; JIaj. X. Hist. Ser. 6. Vol. ix. 28 



