ON SOME TEERESTRIAL ISOPODS IN THE UNITED 

 STATES NATIONAL MUSEUM 



By Hans Lohmander, 



Of Lund, Stoeden 



Having devoted much time to the study of the Trichoniscidae of 

 northern Europe, I desired also to know something of the species 

 of this family of terrestrial Isopods that had been found in North 

 America. Through the friendly assistance of Dr. Waldo L. Schmitt, 

 curator of marine invertebrates, a series of specimens was sent to 

 me for study from the United States National Museum. My ex- 

 amination of this collection has given rise to the following article. 



In the North American collection I have found three species 

 more or less widespread in Europe, Trichords(ym pusillus Brandt, 

 Trichoniscus fygmaeus Sars, and Haplophthalriius danicus Budde- 

 Lund, and two species foreign to Europe, Triehmiiscus papilldcornis 

 Richardson and Brackenrictgia cavernarum Ulrich. 



It is reasonably certain that at least two of the species first men- 

 tioned, Trichoniscus pygmaeus and HaplopMhalrrms danicus, have 

 been brought to North America from Europe with garden produce, 

 etc. In the greater part of their European ranges these species also 

 bear an obviously synanthropic character and are to be found most 

 frequently in hothouses, gardens, graveyards, etc. 



With respect to Trichoniscus pusillus it is more difficult to arrive 

 at a definite conclusion. Its presence and distribution in North 

 America is first to be carefully considered. It seems, however, re- 

 motely possible that this species — occurring over the whole of central 

 and northern Europe and being the most common of all the ter- 

 restrial Isopods found in the Scandinavian countries — may also be 

 indigenous in the eastern parts of North America. 



Trichoniscus papillicornh Richardson, which thus far has been 

 found only in the extreme northern portion of the Pacific Ocean 

 (Bering Island and Cook Inlet) has on a close examination been 

 found not to be a Trichoniscus. It belongs to the family Scyphacidae 

 and is nearly allied to certain species of terrestrial Isopods which 



No. 2713.— Proceedings U. s. National Museum, Vol. 72, Art. 17 



55225—27- 1 ^ 



