156 KANSAS UNIVEESITY SCIENCE BULLETIN. 



reference to local factors, as temperature, purity and rapidity 

 of stream, direct and detailed observations are very scanty, 

 while conclusions as to distribution in the broader sense, the 

 range of species, groups, and the genus itself, are limited by the 

 unexplored condition of much of the territory. 



On the subject of distribution of the crayfishes in its eco- 

 logical phases, very little has appeared. Faxon ('85) observes 

 the occurrence of the same species in the head waters of streams 

 on the opposite side of a watershed, as has been observed in 

 fishes, and gives as examples C. extranevs and • C spinosus in 

 the upper waters of the Santee, Alabama and Tennessee rivers, 

 and also that the forms of the upper and lower part of a river 

 may be different. As illustrations of this, he gives C. bartonii, 

 C. latimanvs, C. acuminatus and C. spinosus in the upper por- 

 tion of the Santee river, while in the lower portion of the same 

 basin live C. hlandirtgii acutus and C. troglodytes. Various minor 

 notes have appeared upon the occurrence of different species in 

 different types of localities, but these are for the most part too 

 meager to be considered in a very general summary. The ob- 

 servations will be found under the species concerned. Ganong 

 ( '87 and '89) has discussed the distribution of C. bartonii, the only 

 species found in New Brunswick. After giving the localities 

 (see catalogue), he says : "The crayfish has probably been in- 

 troduced into this province by way of the AUegash from the 

 head waters of the Penobscot. 'The St. John and Penobscot are 

 connected by a canal from Telos lake to Webster pond, and the 

 divide between the head waters of the Penobscot and the Kenne- 

 bec is so low that it is said that in very wet seasons their waters 

 intermingle.' It has probably spread into the Restigouche by 

 way of Grand river, and into the Miramichi by way either of 

 the Nashwaak or of the Shiktehawk or Beccaguimec. Where 

 the sources of these streams are so near each other, and inter- 

 lock in such a fashion as they do, there would be little difficulty 

 in the animal spreading from one to the other, particularly 

 where the divide is low." 



A case of direct observation upon the relative distribution of 

 different species is given by Williamson ('01), who says, under 

 C bartonii robustus: "Observations indicate that this variety 

 occurs in streams in which both bartonii and propinquus occur, 

 the variety being found in that part of the stream where the 



