Sept. 2 2, iSSi] 



NA TURE 



48: 



old naturalist contrived to group together nearly all the 

 Arthropods known to him and which agreed almost solely 

 in the one point of the non-possession of wings, we find 

 under the genus " Aranea" only 47 species indicated, 

 and of these only 9 are from outside Europe. In the 

 second edition of the "Fauna Suecica" (1761) we find 

 33 species indicated for Scandinavia. Thus six years 

 later all the spiders known to Linnd from outside his 

 native country amounted to 14 species ! At the present 

 time 518 species are recorded as British, and a still 

 almost unexplored region of the Eastern Archipelago has 

 contributed nearly as many from the researches of one 

 or two naturalist-travellers, with whom spider-collecting 

 was certainly not considered of first importance. And 

 yet, notwithstanding the vast and rapid strides that 

 arachnology has made within the twenty years past, 

 the number of workers is still small. The subject is not 

 always an attractive one to naturalists, and is often re- 

 pugnant to non-naturalists, with whom a passion for 

 collecting or studying spiders is seldom associated with 

 respect for the naturahst thus smitten. But all this is 

 rapidly changing, and no two men have done more to 

 bring this about than the authors of the books noticed 

 below. 



In vol. xxi. p. 273, we noticed vol. i. of Mr. Pickard- 

 Cambridge's work ; vol. ii., completing it, is now before us. 

 The whole is dedicated to John Blackwall, and the second 

 volume must have appeared about the time of the decease 

 of that venerable naturalist. A postscript notices some 

 species new for the county or for Britain, and there are 

 additional remarks on senses and economy, in which 

 "sight," " touch and hearing," "power to utter sounds," 

 " venom," " modes of forming snates," &c., are severally 

 alluded to. With regard to " venom," the author ex- 

 presses his firm belief that the bite of the common garden 

 geometric spider {Epcira diademaid) is attended by the 

 emission of a poisonous fluid, sufficiently strong to cause 

 visible effectson the skin of his young son, but without effect 

 upon his own. He now agrees with the conclusion that 

 currents of air play a great part in enabling spiders 

 to carry their lines across from one object to another, 

 although previously he was of opinion that the lines were 

 carried across by the spiders themselves. As we re- 

 marked when noticing vol. i., it is a pity the author did 

 not intercalate the descriptions of those British species 

 not yet found in Dorsetshire amongst the others, instead 

 of placing them in appendices at the end. This would 

 have vastly increased the usefulness of what is still a 

 most useful work, and while not destroying its local in- 

 tentions (as indicated by the title) would have rendered 

 it more distinctly a Manual of British Spiders, for such 

 it really is. With it and Blackwall's magnificently illus- 

 trated Ray Society monograph before him, no student 

 of our spider-fauna should be at a loss to determine, with 

 approximate certainty, any species he may come across. 

 The six plain plates are excellent, engraved from the 

 author's own drawings, and representing many of the prin- 

 cipal genera, with copious details. The index is full. The 

 author recognises 518 species of spiders as inhabiting 

 the British Isles, of which 373 have been found in Dor- 

 setshire. The distribution of these amongst the several 

 families is strikingly unequal. Thus we find three 

 families represented by only one species each ; another 



by only three species. On the other hand the Tlterid- 

 eides claim 267 species, the Drassides 56, the Epeirides 

 32, and so on. Possibly this is the first time that any 

 thoroughly local society has undertaken to bring out a 

 manual of a large group of British animals ; so much 

 the more to the credit of the Dorset Society for initiating 

 so laudable a scheme. Their undertaking, so well con- 

 cluded, is not of local (or even British) interest only, but 

 will have to be considered by every European student of 

 Arachnida. 



In Dr. Thorell's bulky memoir (which forms vol. xxii. 

 of the Annali del Miisco Civico di Cenod) the author 

 continues his studies on the Spiders of the Eastern 

 Archipelago. The descriptions are worked out with 

 his well-known detail and accuracy. Most of the mate- 

 rials result from the exploring voyages of D'Albcrtis 

 and Beccari, and the flourishing society under whose 

 auspices the volume is published deserves the highest 

 credit for the promptness with which it is making known 

 to the scientific world the riches acquired during the 

 Yoyages of these renowned travellers. The descriptive 

 portion is preceded by a bibliographical sketch of what 

 was previously known from the regions, with an analytical 

 and comparative examination of the arachnid fauna gene- 

 rally, still further subdivided in a series of tables at the 

 end ; 317 species are noticed as in the collection (of which 

 173 appeared to be new to science), viz. 252 from Austro- 

 Malesia and 82 from Cape York, but 505 are recorded for 

 the whole of that part of the globe, divided as follows : — 

 Orbitetaria:, 162 species ; Retitelaria, 38 ; Tubitelaria. 

 31 ; Territelaria, !o ; La/erigradcc, 84 ; Citigradcc, 29 ; 

 and Saliigrada", 151. Some idea of the riches of the 

 fauna in this particular respect may be gathered from the 

 fact that no less than eighteen species of the extraor- 

 dinary genus Gasteracantha are described. We cannot 

 resist a few words of admiration at the manner in which 

 the publications of this Italian society are got up, the 

 more so as the printing is done at the Deaf and Dumb 

 Institute of Genoa (Istituto Sordo-Muti). Paper, typo- 

 graphy, and editing alike leave nothing to be desired. 



LETTERS TO THE EDITOR 



\The Editor does not hold himself responsible for opinions expressed 

 by his correspondents. Neither can he ttndei'take to return, 

 or to correspond -villi the writers of, rejected manuscripts. 

 No notice is taken of anonymous coinvntnications. 



[ The Editor urgently requests correspondents to keep their letters 

 as short as possible. The pressure on his space is so great 

 that it is impossible othenvise to ensure the appearance even 

 of communications containitig interesting and novel facts.\ 



The Oldest-known Insects 



I MUST ask your permission to correct the errors into which, 

 your correspondent, Dr. Hagen, has fallen respecting the Erian 

 (Devonian) beds near St. John, New Brunswick, holding certain 

 fossil insects described by Dr. Scudder. 



The Dadoxylon sandstone and Cordaite shale of the vicinity 

 of St. John have been studied not only by myself, but by so 

 good geologists as Prof Hartt, Prof. Bailey, and Mr. Matthew, 

 and by the officers of the Geologic! Survey of Canada; and 

 their stratigraphical relations have been illnstrated by maps and 

 sections, not only in my "Acadian Geology," but in the Reports 

 of the Geological Survey, more especially those for 1S71 and 

 1S75. They have, besides, been thoroughly exposed and ran- 

 sacked for fossils by expensive quarrying operations undertaken 

 by the Natural History Society of St. John, and their plants have 

 been described and compared in detail wiih those of the neigh- 

 bouring Carboniferous formations in my Report " On the Devo- 



