OBSER YA TIONS ON THE AST A CtDJS—FA XOK. 6 fi, r ) 



White, in his " List of the Specimens of Crustacea in the Collection 

 of the British Museum." 18-47, page 71, gives u Potamobius europceus 

 Leach, Edin. Euc." as a synonym of Astacus fluviatilis. This seems to 

 be an error. Leach's article, "Crustaceology," in the seventh volume 

 of the Edinburgh Encyclopaedia, was published in 1814. The European 

 crayfish is there called Astacus fluviatilis; the name Potamobius 

 europceus does not appear. 



Subgenus CAMBAEOIDES Faxon. 

 Cambaro'ides Faxon, Proc. Amer. Acad. Arts and. Sci., XX, p. 150, 1884. 

 Type, Astacus japonicus De Haan. 



ASTACUS (CAMBAROIDES) SIMILIS Koelbel. 



Astacus (Cambaro'ides) similis Koelbel, Anzeiger d. kais. Akad. d. Wissensch. in 

 Wien, math.-naturw. Classe, 29ter Jahrg., 1892, pp. 176, 177; Sitzungs- 

 berichte, CI, Pt. 1, 1892, pp. 650-656, figs. 1, 2, 4, 5, 7-11. 



There are three specimens (two males, one female) of this species in 

 the United States National Museum, collected by P. L. Jouy near 

 Fusan, and at Seoul, Korea; Koelbel's specimens came from the Prov- 

 ince of Kjong-Kwi-do, Korea. 



The Korean crayfish is exceedingly close to Astacus japonicus. The 

 only constant differences appear to be these: In A. japonicus the ros- 

 trum terminates in a minute horny denticle, and the lateral margin 

 bears a similar denticle 1 on each side, a little way behind the apex, 

 while in A. similis the lateral denticles are wanting. The fingers of A. 

 japonicus are a little shorter than those of A. similis and there is some 

 difference in the form of the first pair of abdominal appendages (See Plate 

 X, fig. 10, of my "Revision of the Astacidaj" and figs. 8, 9 of Koelbel). 

 The other differences pointed out by Koelbel are not constant; the 

 median rostral carina is more pronounced in two of the specimens of 

 A. similis in the National Museum than in any of the nine specimens of 

 A. japonicus that 1 have seen, and in one of the three Korean specimens 

 the spine on the inner branch of the sixth abdominal appendage is as 

 far removed from the margin as it is in A. japonicus. 



In two of the examples in the United States National Museum 

 (including the largest one of the three) the rostrum is shorter than the 

 antennal peduncle. 



Subgenus ASTACUS. 



ASTACUS KLAMATHENSIS Stimpson. 



Klamath River, Siskiyou County, California; Umatilla River, Pendle- 

 ton, Oregon; Hangman Creek, Tekoa, Washington; Dart's Mill, Little 

 Spokane River, Washington ; Cceur d'Alene Lake, Idaho (Coll.U.S.N.M.). 



Specimens from the Walla Walla River at Wallula, Washington, and 



1 According to Koelbel (Sitzungsber. d. kais. Akad. d. Wissensch. in Wien, CI, Pt. 1, 

 p. 651, fig. 3) there are two denticles on each side of the rostrum in some specimens of 

 A. japonicus. 



