666 PROCEEDINGS OF THE NATTOXAL MUSEUM. 



from Potlatcli Creek, at Lewiston, Idabo, with the general facies of A. 

 klamathensis, show certain characters of A. troH-hri(h/ii. For instance, 

 in most of them the posterior pair of postorbital spines is very evi- 

 dent, Avhile the rostral spines, the apical spine of the antennal scale, 

 the external spine of the second segment of the antenna, and the spine 

 at the anterior internal angle of the carpus are much more strongly 

 developed than in typical specimens of A. Mamathensis. 



ASTACUS TROWBRIDGII Stimpson. 



A large female specimen, 138 mm. long (Coll. U.S.]S".M.), said to 

 have been taken from a bunch of seaweed in salt water at Monterey, 

 California, approaches A. leniusculus in three respects, namely: The 

 posterior pair of spines on the back of the carapace, behind the eyes, 

 are rather more strongly developed than in the typical A. troichridgii ; 

 the rostral acumen is as long as in A. lenlxsculus : the tubercle at the 

 orifice of the green gland ends in a sharp, horny point. In other 

 respects this specimen agrees with A. trowhrulgii. The body is very 

 broad across the branchial region, and there are three spines on the 

 left side of the telson, two on the right. There is a rudimentary limb 

 on the right side of the first abdominal segment, a condition seldom 

 seen in the American species of Astacus. 



Antaeus troichridgii has been previously known only from the region 

 near the mouth of the Columbia Kiver. 



ASTACUS LENIUSCULUS Dana. 



There is a large female, 122 mm. long, from San Francisco County, 

 California, in the collection of the California Academy of Sciences (No. 

 3259). The right and left chelipeds of this specimen are of equal size; 

 the upper margin of the right merus is armed with two spines, of the 

 left merus with three spines; the telson is armed with one spine on 

 the right side, two on the left. This species has been previously 

 recorded from the Columbia Kiver and Puget Sound. 



ASTACUS GAMBELII (Girard). 



Crawfish Creek, at Moose Falls, one mile above junction with Lewis 

 Eiver, Yellowstone National Park, Wyoming; Snake River, just south 

 of Yellowstone Park, Wyoming; Mink Creek and Port Neuve River, 

 Pocatello, Idaho; Shoshone Falls, Idaho; Blue Lakes, four miles below 

 Shoshone Falls, Idaho (Coll.U.S.N.M.). 



All of these localities are in the Snake River drainage. 



ASTACUS TORRENTIUM (Schrank). 



Recorded from Cologne, Germany, and from St. Gallen, eastern Switz- 

 erland, by Doctor A. P. Ninni.^ 



' Atti delta Soc. Italiana di Sci. Nat., XXIX, pp. 322-326, 1886. 



