1864.] 577 



Cecidomjjia might serve a useful purpose towards dispelling that illu- 

 sion. 



A. Front h of pupal integument whitisli like 

 the abdomen. (Larva varied with yellowish or 

 orange.) 



1. Hair of thorax blackish in the imago No. 1, C. s. brassicoides, n. sp. 



2. Hair of thorax whitish in the imago. 



f Origin of the anterior branch of the .3rd 



longitudinal wing-vein obsolete No. 2, C. s. strobiloides, n. sp. 



tf Origin of the anterior branch of the 3rd 

 longitudinal wing-vein pretty distinct. 



a. Cocoon \h — 2 times as long as the 



larva No. 4, C. s. gnaphalioides, n. sp. 



b. Cocoon 2J — 3 times as long as the 



larva No. 5, C. s. rhodoides, n. sp. 



B. Front i of pupal integument pale dusky.* 



(Larva varied with sanguineous.) No. 8, C. s. siliqua. n. sp. ? 



GALLMAKERS.— Genus CECIDOMYIA, Subgenus CECIDOMYIA. 



No. 1. Gall Salicis brassicoides. n. sp. — On Salix longifolia. Monothalamous, 

 sessile galls, expanding each J — 2\ inch, and with the general outline of each 

 spherical or oval, growing in a more or less close-set bunch of 1 — 11, like the 

 sprouts of a cabbage-stump, on twigs which vary in diameter from .10 inch to 

 .50 inch, sometimes from their tips but more generally from their sides, and 

 often with several minute twigs growing from the midst of each bunch of galls, 

 the largest galls generally on the largest twigs. The leaves composing each 

 gall are all sessile, and are on the outside ovate lanceolate or lanceolate, and 

 widely expanded and towards their tips recurved. Towards the tip of the gall 

 they become smaller, slenderer, and gradually less expanded, and in the centre 

 they are quite small, perfectly straight and linear-lanceolate, closely embracing 

 the central cell containing the author of the gall. External leaves with the mid- 

 rib, and generally some of the branching side-veins, pretty distinct. It is but very 



"*" It must not be supposed that this infuscation is causeless and accidental. 

 There is a cause for every natural i^henomenon, if we can only discover it: and 

 the reason why the anterior parts of the pupal integument are in this species 

 strongly tinged with fuscous, instead of being whitish hyaline, as in o'her allied 

 species, is that tliey are thickened: and the reason that they are thickened is, 

 that the jiujia has to make its way out through the narrow, woody tube at 

 the tip of its gall, instead of through soft and yielding leaves as in the case of 

 species Nos. 1 — (3. In the same manner, as will be noticed below, the antennal 

 horns of those species that have to work their way out through dense sponge or 

 wood (C .s. batatas n. sp. and Cec. cornuta n. sp.) are thickened and blackened 

 in the pupal integument. We must remember that the pupal integument of an 

 Insect bears the same relation to the pupa itself, that the prepared skeleton of a 

 Mammal bears to the Mammal itself. 



