654 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xx 



coarsely punctate and armed along its inner border with a double 

 row of spiniform tubercles. The fingers are excessively long, the 

 dactylus being more than three times as long as the inner margin 

 of the palm; the fingers meet only at their tips, which cross each 

 other; the grasping edges of both fingers are furnished with blunt 

 teeth, irregular in size, while the opposite margin (or margin toward 

 the median line of the body) of the dactylus is armed with two longi- 

 tudinal rows of acute teetb. The external finger is barbate within at 

 the base. 



The first abdominal appendages of the second form of the male are 

 long and slender, their tips lying between the second pair of legs 

 when directed forward. The outer branch is longer than the inner 

 branch. The tips of both branches are distinctly recurved. 



The annulus ventralis of the female is triangular, with a deep trans- 

 verse central fossa. The anterior wall is indistinctly bituberculate, 

 the .posterior wall thickened and divided by a median longitudinal 

 sigmoid closed fissure. The claws of the female do not differ in form 

 from those of the male. 



Dimensions of a male, Form II: Length 81 mm.; length of carapace 

 41 mm.; length of rostrum 13 mm., width of rostrum 4.5 mm.; length 

 of rostral acumen 6 mm.; distance from tip of rostrum to cervical 

 groove 28 mm.; distance from cervical groove to posterior border of 

 carapace 13 mm.; width of areola at its narrowest 0.5 mm.; length of 

 cheiiped 67.5 mm.; length of merus 15.5 mm.; length of carpus 10 

 mm.; length of chela 35 mm.; breadth of chela 10.5 mm.; inner mar- 

 gin of palm 8 mm.; length of dactylus 25.5 mm. 



Tbe largest specimen (a female) is 101 mm. long; the large claw 

 measures 47.5 mm. in length, the dactylus 36 mm. 



Oxford Bend, White Kiver, Arkansas. (Coll. Mus. Comp. Zool.) Four 

 males, Form II; four females, six young. 



This clearly characterized species, discovered by Professor S. E. 

 Meek, is related to G. virilis, with which it agrees essentially in the 

 form of the sexual parts, both male and female, and the areola. It is 

 readily distinguished from G. virilis by its longer, parallel-sided ros- 

 trum, with longer lateral spines and acumen, as well as by the excessive 

 length and slenderness of the fingers. In many individuals the chelre 

 are unequal in size on the right and left sides, the right beiug com- 

 monly the larger. 



In recent alcoholic specimens the fingers are clouded with dusky, and 

 a large spot or blotch of the same hue is seen on both sides of the hand 

 near the articulation with the wrist. 



CAMBARUS IMMUNIS Hagen. 



Small stream flowing into Oneida Lake, New York (No. 4330, Mus. 

 Convp. Zool.). Sandusky, Erie County, Obio (No. 5038, Mus. Comp. 

 Zool.). Northern Ohio, near shore of Lake Erie; Ames, Story County, 

 Iowa; South Bend, Cass County, Nebraska (Coll. U.S.N.M.). Also 



