Teras terminalis. 77 



females, others only males. It seems probable also 

 that some specimens of Biorhiza aptcra produce only 

 males and some only females. We are therefore driven 

 to admit that the sexes are differentiated in the ^%g, 

 and that this phenomenon cannot be referred to any 

 other influence, such as different or more abundant 

 nourishment of the larvae. 



[The oak apple is found in May on Qiierciis pedunciilafa, O. sessi'h- 

 flora, and Q. pubescens. According to Mayr, the gall-makers, as well 

 as the inquilines and some parasites, make their appearance in the 

 end of May or the beginning of June. In June the Rosechafers 

 {Cetonid) eat their way into these galls, consuming the outer spongy 

 tissue, and leaving the inner cells adherent to each other. From 

 these inner cells parasites are produced in the second year. A large 

 caterpillar, probably of a Noctua, sometimes consumes the whole 

 interior of the oak apple. 



Mr. Francis Walker gives the following list of insects inhabiting 

 oak apples : — 



June (1845'. Nttidula grisea, Balaninus glandium, Forficula auri- 



cularia, Psocus subocellahis, Atropos ?, Synergus socialis, and 



specimens of two or three other species of Cynipidae, Pteronialns 



Nanbohis, Pterojtialns ?, Pteronialns seniifascia, Ptcrornahis ovatiis, 



Pteroyyiahis domcsiicus, EnpeUniis ttrosonns, Eulophns gallamm, Ceci- 

 doniyia 2 sp., Tortrix viridana. 



July. Physoevria ?, JSitidida grisea, Latrtdius lardarhts, Corti- 



caria transversalis, Carpalimus fuliginosus, Aleochara ?, Orchestcs 



quercns, Pirnpla 2 sp., Heniiteles areator, Synergus socialis, Decatonia 

 immaculata, Megastigmits dorsalis. Callinionie cingidatus, viridissinius, 

 parellinus, inconstans, confinis, minutus, exilis, chlorinus, tniitabilis, 

 latus, lettcopteriis, abdominalis, leptocerus, aiitmiinalis. Pteronialns 

 Naitbolus, dilectus, fuscipcnnis, fasciiventris, ovatus, hilaris. Eiipelmus 

 urozonus. Tctrastichus diaphantes. Eulophns gallarunt, Agatliyllus 



? sp. Inostemma Boscii. Ceraphron ?. Drosophila ?. Lozo- 



taeiiia xylosteana, Zeiraphtra communana. Chaetochilus sylvellus. 

 Pentatoma lurida. Anthocoris netnorum. A few Arachnidae and 

 .^mn' of such species as dwell under the bark of trees. 



August. Dromius quadrimacutatus. Cryptophagus cellaris. Corti- 



caria transversalis. Microgaster ?. Aphidius ?. Synergus 



socialis. Decatoma immaculata, Megastigmits dorsalis, Callimome, 



