28 ENTOMOLOGICAL SOCIETY 



while such a feature is abnormal under the circumstances, it is 

 no more so than many of the other features of Platypsyllus. 



In the discussion of this subject, Mr. Schwarz held that, if 

 not the ultimate larva of Platypsyllus, it is certainly Coleopter 

 ous, and cannot be referred to the Mallophaga, In the Coleop- 

 tera, the Staphylinid genus Amblyopinus is known to be par 

 asitic on terrestrial rodents, two species having been found 

 in the fur of mice and rats, one in South America and the other 

 in Tasmania. We might reasonably expect to find this genus 

 in North America under similar circumstances, but a glance 

 at Prof. Riley's larva shows that it cannot possibly belong to 

 the Amblyopinus nor to any other genus of Staphylinidae. 



Dr. Marx read the following paper : 



A CONTRIBUTION TO THE KNOWLEDGE OF NORTH 

 AMERICAN SPIDERS. 



BY DR. GEO. MARX. 



In a large collection of natural history objects from all parts 

 of this country the student will find some specimens, which,, 

 by their peculiar and strange morphological features, he cannot 

 place in any of the established families. They lie, conse 

 quently, buried in the collection, and are thus lost to science. 



I possess in my collection of North American Arachnida a 

 number of such new forms, which I have hitherto been unable 

 to place in any established family. The principal cause of this 

 difficulty is that the American Arachnologist has still to fol 

 low the classification of the European Arachnida, and that no 

 attempt has so far been made to work out, independently, a sys 

 tematic arrangement, based upon the spider fauna of America. 

 Mr. B. Simon has lately published a list of families of extra- 

 European Aranese in a systematic order,* and he has promised 



f * Simon, in his " Remarques stir la Classification des Araignees " 

 (Etudes Arachnologiqu.es, 22e memoire, Annales Soc. Bnt., France, 

 1890, p. 79), presents a "succinct tableau " of the families of Aranece, 

 including those which he had to establish for extra-European Spiders. 

 He withdraws two of his former suborders, the GnaphosfC and Ocu later 

 (L,es Arachnides de France, Vol. I, p. 14), leaving only the Theraphosce 

 and the Aranece verce. These latter denominations Simon prefers in 

 place of Tetrapneumdnes and Dipnemuones, as these names indicate 

 some characters which are subjected to some exceptions, e. g., Hypochi- 

 lidce, which he places amongst the Aranefe vera. The author divides 

 the hitherto described spiders into thirty-nine families, of which eighteen 

 are established upon exotic genera. 



