lUO MICHIGAN SURVEY, 1905. 



SPIDERS AND INSECTS FROM THE PORCUPINE MOUNTAINS 

 AND ISLE ROYALE, MICHIGAN. 



A. G. RUTHVEN. 



With the exception of the Odonata and Orthoptera, no attempt was made 

 to make extensive collections of the different groups of invertebrates, and 

 the lists comprise only the more characteristic forms in the different habitats 

 studied. The collections were, for the most part, made by the author 

 with the assistance of the other members of the party, except in the case 

 of the ants which were collected largely by Mr. Otto McCreary. We are 

 indebted to the following persons for the determination of the collections: 



Spiders. — Mr. Nathan Banks, U. S. Department of Agriculture. 



Dragonfiies. — Mr. E. B. Williamson, Bluffton, Ind. 



Butterflies and Moths. — Prof. Arthur J. Snyder, Springfield, Idaho. 



Ants. — Dr. W. M. Wheeler, American Museum of Natural History, 



1. SPIDERS FROM THE PORCUPINE MOUNTAINS. 



1. Gnaphosa conspersa Thor. III. 1. Taken under a pine log among the 

 dwarf huckle-and blueberry bushes in the aspen zone, August. 6. 



2. Linyphia phrygiana Koch. I. Taken on the leeward side of pro- 

 jecting outcrops of rock on the beach of Lake Superior, July 2L Also 

 occurs in Evirope (Banks). 



3. Epeira trifolium Hentz. I. This spider occurs numerously along 

 the beach of Lake Superior. It weaves its web behind projecting out- 

 crops of rock, and when surprised runs swiftly into the rock crevices. 

 The webs are often filled with small white moths, July 30. 



4. Epeira patagiata Clerck. I. This species was found under the 

 same conditions as Epeira trifolium. Also occurs in Europe (Banks). 



5. Lycosa gracilis Bks. III. 1. In a shallow hole in dead grass under 

 a fallen pine log in the aspen zone, August 6. 



6. Parclosa lapidicina Th. I. This species was taken on the beach of 

 Lake Superior, July 30. It was observed quite frequently running about 

 over the rocks, and dodging into the crevices when pursued. 



7. Pardosa. sp. (probably lapidicina). I. Several immature specimens 

 were taken on the rocks of the Lake Superior beach, July 2L 



8. Dolomedes tenebrosus Hentz. II. 1. A specimen of this spider with 

 its egg mass was taken on a cedar stump in the arbor vitae swamp, August 25. 



2. SPIDERS FROM ISLE ROYALE. 



1. Amaurohius sp. V. One specimen was found in the Sphagnum 

 moss in a tamarack swamp, August 22. 



2. Amaurohius hennetti Blackw. II. One specimen was taken in the 

 moss ground cover of the balsam and spruce forest on the flood-plain of 

 Washington river, August 26. 



