330 MICHIGAN SURVEY, 1908. 



the amphibian and reptile faunas. As in the case of the fish, the species 

 are all of general distribution in northeastern North America, but, 

 with the exception of the mud puppy, none of the species recorded from 

 the island are aquatic, and, as they also belong to groups which are 

 very sensitive to cold, they could neither reach the island through the 

 water in summer or over the ice in winter. The theory of involuntary 

 transportation thus seems to be the only tenable one. At present the 

 most plausible explanation for the presence of the reptiles and amphi- 

 bians (with the exception of the mud puppy, which might swim across) 

 found on the island is that they have been transported on driftwood. 

 Unlike several of the other groups of animals, and the flora, the 

 amphibian-reptile fauna is not strongly boreal in its aflSnities. It is 

 true that the forms which are found on the island also range to the 

 northward, but the principal range of the species is to the southward, 

 and only one species (Rana septentrionalisj does not extend rather far 

 south in eastern North America. The southern afSnity of this fauna 

 is undoubtedly due to the fact that the amphibians and reptiles are both 

 pre-eminently warm climate groups, and the representatives in. this 

 region are those few that are able to endure the colder climate. 



ANNOTATED LIST. 



Pisces. 



1. Catostomiis commersonii (Lac^p^de). Common Sucker. Taken 

 in the southeast coves of Rock Harbor (III. 6). As this species was 

 found in a similar habitat at the south end of the island in 1904, it is 

 undoubtedly to be found in all of the suitable bays and coves along 

 the shores, and probably also in the larger inland lakes. 



2. Pimephales promelas Rafinesque. Black-head Minnow. Speci- 

 mens of this fish were taken in Sumner Lake (III. 5). This is the only 

 locality known for the island. 



3. Leuciscus neogarns (Cope). As in the case of the Black-head 

 Minnow, this species was only taken in Sumner Lake (III. .5). 



4. Coregonus quadrilateralis Richardson. Menominee Whiteflsh. 

 This species, a common food fish in Lake Superior, was taken in Siskowit 

 Lake (V). 



5. Argyrosomus artcdi (Le Sueur). Lake Herring. Taken by the 

 1905 expedition in Rock Harbor and Lake Desor (VII. '04). Like the 

 Sucker this fish, which is a common Great Lakes species, probably occurs 

 in most of the larger inland lakes. 



6. Argyrosomus vignpinn4s GiW. Blue-fin; Black-fin. This fish was 

 only found in Rock Harbor. 



7. Cristivomer namaycush (Walbaum). Mackinaw Trout; Lake 

 Trout. Adult specimens were taken in. Rock Harbor, and a single im- 

 mature specimen (41 mm. in length) in Benson Brook (II. 1). 



8. Salvelinus fontinalis (Mitchell). Brook Trout. The 1905 expedi- 

 tion secured specimens of the Brook Trout only in Benson Brook (II. 1). 

 As it was found on the southern end of the island, in Washington Harbor 

 and river, in 1904, it may be considered as occurring throughout the 

 length of the island, in suitable habitats. 



9. Tjtidvs liicms (Linnaeus). Common Pike; Pickerel. Taken in Sar- 

 gent Lake. This is apparently the only Isle Royale record. 



