ENTOMOLOGY. 305 



Adelops, a species of Phalangopsis, and flics of the genus Anthomyia. It is 

 a remarkable circumstance that in most of these creatures the eyes arc 

 either wanting entirely (Anophtlialmus, Anthrobiu, Phalangodes), or at least 

 very imperfect (Adelops, Astacus.} As the animals, almost without excep- 

 tion, differ specifically, or even geuerically, from those living on the surface 

 of the earth, there is evidence of a peculiar subterranean Fauna existing, our 

 very limited acquaintance with wliich is much extended by these two com- 

 munications. 



These productions of the Mammoth cave in general have little resemblance 

 to those of the caves of Cariuthia. Only the genus Auophthabnus, a very 

 similar species of which has been found contemporaneously in the Lueg 

 Grotto, is common to the caverns of both hemispheres ; probably also the 

 genus Adelops ; at least the Berlin Museum possesses two European species 

 of it, but their history is unknown. [A brief notice of some of these is given 

 also in the Annals of Natural History, xiv, 111.] 



An instructive treatise by Platner, Notices respecting 

 the Respiratory Organs and the Skin in Silkworms (Mull. 

 Arch. Anat. p. 38, pi. 3), has for its subject the structure 

 of the tracheae (air-pipes) in particular. 



The author believes the spiral thread to consist not of cellular but of 

 nuclear fibres, i. e. fibres composed not of cells but of the nuclei of cells 

 [vesicles]. Regularly a new spiral fibre is formed between two pre-existing, 

 which shows how every branch of the tracheae commences with a new spiral 

 thread. At the same time the branching of the tracheae usually is not 

 ramuscular [i. e. by smaller branches given off at the sides], but commonly a 

 single branch splits into two. Frequently also a branch is subdivided into 

 a number of finer fibres. The course of the tracheae is very tortuous, par- 

 ticularly that of the finer fibres, in which all terminate at last, and which 

 resemble a spiral spring uncoiled. These fine threads never pass into each 

 other (anastomose). Their diameter is pretty nearly that of the spiral fibre 

 in the tracheae themselves, and the author infers that the slender extremities 

 of the tracheae are composed of their spiral fibre merely, and that the tracheae 

 form a tube only so long as the coils of the spiral are contiguous. Special 

 attention also is given to the distribution of the tracheae to the ner- 

 vous system. Every ganglion receives from beneath, at each of its 

 sides, a stout branch of the trachea, which is accompanied by a blood- 

 vessel, (the author remained in doubt about the latter, the presence of 

 wliich the Reporter is able to confirm, and that it terminates in the main 

 trunk which accompanies the spinal chord [rachis.] ) Detached trachea; 

 resolve themselves into fibres, which are so closely matted about the gan- 

 glion that the entire mass of nerve is enveloped by them. In the skin of 



20 



