of certain species of WiUoic. — Part 2nd. 285 



cosmopolites, the Gall-gnats and the Mites — I know of no gall on Cle- 

 Viatis (Virgin's-bower), on Fraxinus (Ash), on Betula (Birch), on Pla- 

 tanus (Plane-tree), on Juglans (Walnut), on Pyrus (Apple, Pear, &c.), 

 on Crataegus (Thorn), on Prunus (Plum), on Cerasus (Cherry), on 

 Persica (Peach), on llibes (Currant and Gooseberry), on Syringa (Li- 

 lac), on Corylus (Hazel), on Ostrya (Hop-hornbeam), on Morns (Mul- 

 berry), on Madura (Osage-orange), on Robinia (Locust), on Gledit- 

 schia (Honey-locust), on Cercis (Kedbud), on Gymnocladus (Coffee- 

 tree), on Tilia (Basswood), on Viburnum (Black-haw, Snowball-tree 

 or Guelder-rose, &c), on Lonicera (Honey-suckle), on Sambucus 

 (Elder), on Cephalanthus (Button-bush), on Ceanothus (Red-root), 

 on Euouymus (Burning-bush), on Ptelea (Hop-tree), on Ampe- 

 lopsis (Virginia Creeper), on Xanthoxylum* (Prickly-ash), on Acer 

 (Maple), on Negundo (Box-elder), or on Juniperus (Juniper). f I 

 have enumerated here only those N. A. genera of Trees and Shrubs, 

 with one or more species of which I am familiar— -which I have dili- 

 gently searched for galls — -and in which, if galls existed on the species 

 known to me other than Acaridous and Cecidomyidous galls, I think I 

 should have found them, at all events in the great majority of cases. 

 But even these genera foot up to 33. 



As illustrative of the comparatively general distribution of Acaridous 

 and Cecidomyidous galls, it may be worth while to give the following- 

 abstract of their occurrence, so far as known to me, among; the cenera 

 of the above two lists. — In the first list, Celtis bears 5 Cecidomyidous 

 galls belonging to new and undescribed species. Ulmus bears 3 Acari- 

 dous galls n. sp. Populus bears I Acaridous gall n. sp. Pinus bears 



* Commonly, but incorrectly, spelt Zanthoxylum, though Dr. Gray in his Man- 

 ual gives the correct derivation from the Greek. Evidently the botanist Colden 

 mistook here a J for a (,, just as the entomologist Fitch, when he composed his 

 Cynipidous new genus Philonix (properly Philonips) mistook a \p for a \. Incon- 

 sistently enough, the botanical genus Xanthium, which is derived from the 

 very same Greek root, is always spelt with an X and never with a Z. 



f The Red Cedar belongs to this genus, but I have shown in the Practical En- 

 tomologist, (I, pp. 49 — 51,) that certain gall-like bodies which are attached by a 

 very short peduncle to its twigs, are not Galls, but a congeries of Epiphytous 

 Funguses. On April 8 these reddish-brown sub-globular bodies, which average 

 i— J inch in diameter, had on their surface many circular depressions, often 

 with a very flat central nipple, the specimens (hen cut into being whitish and 

 fleshy inside, but not juicy. On April 28 filaments about & inch long and five 

 times as long as wide, of a cylindrical shape and but slightly tapered at tip. had 

 shot forth from these circular depressions, and were then covered with ferrugi- 

 nous dust, supposed to be the spores. On May 15 these filaments were i inch 

 long, and seven or eight times as long as wide: but already some had fallen off, 



PltOCEEDIXGS ENT. SOC. PHILAD. JANUARY, 1867. 



