422 Miscellaneous. 



capacity of the author's mind. Mr. Gorham, however, is well known 

 among the London entomologists as an acute and highly promising 

 Coleopterist ; and we hope he will work up other comparatively 

 neglected families with the same ability he has shown in the brochure 

 before us. We regret to see that in the preface the author complains 

 of difficulties thrown in his way by the authorities of the British 

 Museum. There must have been some misapprehension ; Dr. Gray, 

 we believe, is as ready now as formerly to assist any one studying 

 the collections under his charge. 



MISCELLANEOUS. 



On the Respiratory Organs of the Araneida. 

 By Dr. P. Bertkau. 



The old division of the Arachnida into pulmonary and trachean, 

 established by Latreille, lost all its value when Leon Dufour, Duges, 

 and, after them, Menge and Siebold discovered that the Araneida 

 possessed tracheae besides their lungs. 



One might be surprised at first to see two different aerial respi- 

 ratory apparatus existing together in the same animal ; but Leuckart 

 soon showed that the so-called lungs ought to be considered a 

 formation homologous with that of the tracheae, and he gives them, 

 in consequence, the name of pulmonary tracheae (Lungentracheen). 

 This interpretation has been generally accepted ; and the new obser- 

 vations of M. Bertkau go also to confirm it. 



The author describes the structure of the lungs, for which he pro- 

 poses on his part the name of laminar tracheae (Fiichertracheen) and 

 that of the tracheae properly so called. From these investigations, 

 which have been directed to a great number of genera and species, 

 he deduces a grouping of Araneida based on the modifications that 

 these animals present in their respiratory organs. We shall not 

 follow him in the description that he gives of the lungs, because it 

 contains nothing but well-known facts. We may recall only that 

 the two stigmata which admit the air into these organs are situated 

 on the lower surface of the abdomen, immediately behind the 

 peduncle which unites that region to the cephalothorax. In some 

 genera there is behind these pulmonary stigmata, and quite close to 

 them, another pair of stigmata. It is only in the Mygalidae that 

 these orifices lead, like the anterior ones, to a second pair of lungs. 

 In Dysdera, Segestria, and Argyroneta they give access to a trachean 

 system. A very short canal, starting from each of them, leads to a 

 wide, compressed, principal trunk, of which the wall is strengthened 

 by chitinous rods, which are either irregularly placed (Dysdera) 

 or united into a spiral thread exactly as in the tracheae of insects 

 (Segestria and Argyroneta). The greater portion of the trachean 

 trunk inclines forward ; a little bursiform appendage is directed 

 backward. In Dysdera and Argyroneta each of the two anterior or 



