412 BRITISH LEPIDOPTERA. 



than a single pupa found at root beneath any one tree (Buckland) ; 

 pupae often most abundant by digging about elms in the avenues 

 and parks in the Reading district (Holland) ; a pupa under bark 

 of plane-tree 4 feet from ground in a firm silken cocoon produced 

 imago June 2nd, 1856, the pupa less rugose than usual (Cox, 

 Ent. Wk. Int., i., p. 28) ; a pupa, March 2nd, 1857, in a cocoon 

 of gnawed bark and wood under bark of old willow, and from 4ft. — 5ft. 

 from ground, the pupa smoother than usual, with a most beautiful purple 

 tinge, produced moth May, 1857, other pupae under piece of bark on 

 elm 4ft. — 5ft. from ground, at Stowmarket (Crewe); more commonly 

 dug under elm than lime, once under sycamore, but other trees 

 near ; a very hardy pupa in confinement, have known injured speci- 

 mens to emerge successfully (Prideaux) ; 3 inches under ground, near 

 trees (J. A. Clark) ; common under elm towards end of September 

 at Calne (Eddrup) ; pupa spun up in an old decayed mat in a 

 garden, 3 pupae in a flowerpot in a toolshed under lime tree, most 

 found by tearing up the grass roots from 12ms. to i8ins. from the 

 trunk (James) ; pupae to be taken freely at the roots of elm in the 

 autumn near Honiton (Riding); common in the Cheltenham district at 

 roots of elm and lime, some 70 pupae dug in 1898 principally at elms 

 (Robertson) ; found commonly at birch and elm, prefers the narrow 

 angles formed by the roots, getting in as far as possible (Greene). 



Pupa. — $. Length 26mm. — 35mm., width S^mm. — 9 '6mm. 

 [This difference in width in two specimens of the same sex may 

 appear trifling, yet the two pupae look, one as if it were a $ pupa, 

 the other quite a starveling.] Some pupae of both sexes have a brilliant 

 shining black aspect, others a dull grey-brown appearance. The 

 majority have more or less of this dull grey-brown muddy and 

 muddled appearance. One specimen gives some clue to the 

 nature of this appearance. In this specimen, a fine superficial 

 scale can be picked off the pupa in small flakes. It is of equal 

 density all over, and extends right down to the bottom of the 

 intersegmental incisions. It is something belonging to the pupa, 

 not, that is to say, any extraneous dirt or other coating picked up. 

 Under the microscope it is of very uniform density, but shows in 

 every detail the surface sculpturing of the pupa. It would appear 

 that the black pupae are those in which this scale is perfectly adherent 

 rather than wanting, and that the brownish coloration is due to 

 its being more or less loose. On pupating, the new pupa is moist 

 with fluid ; this fluid appears to contain chitin, which solidifies as 

 the fluid dries up and forms part of the outer surface of the pupa. 

 I imagine this brown scale is this chitin, which in this species for 

 some reason fails to absolutely consolidate itself with the pupa-skin 

 in a large proportion of cases. The idea that there is a double 

 pupa-skin (as in Ephemera, Sec.) seems an impossible one. 

 The pupa is nearly straight and cylindrical in the sense 

 of having everywhere a circular section, i.e., not anywhere 

 flattened. It is widest at the 4th and 5th abdominal seg- 

 ments; hollowed at the 3rd thoracic and 1st and 2nd abdominal 

 segments, so as to have a certain amount of waist. Still it is of 

 very nearly the same size from the middle of mesothorax to the 

 6th abdominal ; the anterior extremity is rounded dorsally but is 

 fairly straight in front ; the posterior extremity tapers from the 



