8o Searle, Gleanings of a City Naturalists [voTlxxxvi. 



directly into tracheae which ramify through the insect's body. 

 The respiratory organ of a spider is different, inasmuch as the 

 pulmonary stigma leads into cavities which are practically 

 filled with plates attached at the front and sides, but having 

 their posterior edges free. These plates are the leaves of the 

 so-called lung-book. Each leaf is hollow, and its cavity is 

 continuous with the blood sinus, into which ' the blood from 

 various parts of the spider's body is poured. There are similar 

 gill-books in the king crab, Limulus, into which the blood 

 enters, while, externally, the water carrying oxygen in solution 

 circulates between the leaves. 



Crustacea. — ^\Vhen I mentioned Crustacea as a visitor to a 

 city office, some of you, perhaps, had visions of a " cray and 

 chips " supper ; but the crustacean I captured was a living 

 Isopod — one of the wood-lice, or slaters. I cannot account 

 for its presence otherwise than from the fact that my neighbour 

 uses pot plants for decorative purposes, and the stray Isopod, 

 thus, perhaps, introduced into the building, wandered into my 

 office. 



These notes might have been extended to a much greater 

 length, but as they are I think they are sufficient to show 

 that even in a city office there is plenty of material to engage 

 the attention of anyone with a love for natural history if they 

 care to use their eyes, and there is nothing to deter the city 

 dweller from taking up this delightful and intellectual recreation 

 and enjoying the pleasure to be derived from it. 



In putting these notes together free use has been made of 

 "House-Flies," by C. G. Hewitt, D.Sc. ; "Flies in Relation to 

 Disease," by G. S. Graham-Smith, M.D. ; " The Cambridge 

 Natural History," &c., but the facts stated therein have been 

 checked wherever possible by observation and dissection. 



The dissections so made, and from which the photo- 

 micrographs illustrating the paper have been made, are on 

 exhibition under the microscope this evening. 



The following is a list of the insects noted during the last 

 six months : — 



I.epidoptera : Heteronympha merope, Pyrameis kershawi, Dasypodia 

 selenophora, Agrotis spina, A. infusa, Cosmodes elegans, Tineus (sp.) 

 Coleoptera : Anoplognathus velutinus, Phoracantha (sp.), Tenebrio moli- 

 ter, Elater (sp.), Mezium affine, Trosoderma froggatti, Quodius fulgidus, 

 Attagenus pallens, Doretaphrus bakewelli, Ptinus fur, Silodrepa paniceum. 

 Diptera : Calliphora villosa, C. erythrocephala, Pollenia stygia, Unastello- 

 rhina dorsalis, Pvcnosoma rubifacies, Limnophila (sp.), Trimacra (sp.), 

 Chironomus (sp.)", Stegonica (sp.), Culex (sp.) Hymenoptera : Camp- 

 someris anthracina, Ichnenminida (sp.) Hemiptera : Nasius vestitis ; 

 with others not identified. 



