EXPLANATION OF THE PLATES. 



Plate I. First abdominal legs of the male. 



C. acutus, Form I., fig. 1 in front; fig. 2 outside. Form II., fig. 4 in front; fig. 3 the same en- 

 larged; fig. 5 outside. 



C. Clarlii, Form I., fig. 7 in front; fig. 8 outside. Form II., fig. 9 in front; fig. 10 outside. 



C. troglodytes. Form I., fig. 11 in front; fig. 12 outside. Form II., fig. 13 in front; fig. 14 outside. 



C. Lecontei, Form L, fig. 15 in front; fig. 16 outside. Form II., fig. 17 in front; fig. 18 outside. 



C. affinis, Form I., fig. 19 in front ; fig. 20 outside. Form II., fig. 21 in front ; fig. 22 outside. 



C. virilis, Form I , fig. 23 in front; fig. 24 outside ; figs. 25, 26 varieties outside. Form II , fig 27 

 in front ; fig. 28 outside. 



C. juvenilis, Form I., fig. 29 in front; fig. 30 outside; fig. 31 viewed more outwardly. Form II., 

 fig. 32 in front; fig. 33 outside. 



C. propinquus, Form I., fig. 34 in front; fig. 35 variety; fig. 36 outside. Form II., fig. 37 in front; 

 fig. 38 outside. 



C. obesus, Form I., fig. 39 in front; fig. 40 outside. Form II., fig. 41 in front; fig. 42 outside. 



C. latimanus, Form I., fig. 43 in front; fig. 44 outside. Form II., fig. 45 in front ; fig. 46 outside. 



C. Barlonii, Form I., fig. 47 in front ; fig. 48 outside. Form II., fig. 49 in front; fig. 50 outside. 



C. Carolinus, Form I., fig. 51 in front ; fig. 52 outside. Form II., fig. 53 in front ; fig. 54 outside. 



C. versutus, Form I., fig. 55 in front ; fig. 56 outside. Form II., fig. 57 in front ; fig. 58 outside. 



C. spiculifer, Form I., fig. 59 in front; fig. 60 outside. Form II., fig. 61 in front; fig. 62 outside. 



C. Blandingii (Type), Form I., fig. 63 in front ; fig. 64 outside. 



C. angustatus (Type), Form I., fig. 65 in front ; fig. 66 outside ; fig. 67 inside. 



C. pellucidus, Form I., fig. 68 in front; fig. 69 outside. Form II., fig. 70 in front; fig. 71 outside. 



C. obscurus, Form I., fig. 72 in front; fig. 73 outside. Form II., fig. 74 in front ; fig. 75 outside. 



C placidus, Form I., fig. 76 in front; fig. 77 outside. Form II., fig. 78 in front; fig. 79 outside. 



C. ruslicus, Form I., fig. 80 in front; fig. 81 outside. Form II, fig. 82 in front; fig. 83 outside. 



C. affinis, very old (C. Pealei), Form I., fig. 84 in front; fig. 85 outside. 



C. lancifer, Form I., fig. 86 in front; fig. 87 outside. 



C. exlraneus, Form II., fig. 88 in front ; fig. 89 outside. 



C. adcena, Form I., fig. 90 in front; fig. 91 enlarged in front; fig. 92 outside. 



C. penicillatus, Form I., fig. 93 in front ; fig. 94 outside. Form II., fig. 95 in front ; fig. 96 outside. 



A. Gambelii, fig. 97 in front ; fig. 98 outside. 



C. Clarkii (Type), young, Form II., fig. 99 in front; fig. 100 outside. 



C. immunis, Form I., fig. 101 in front; fig. 102 outside. 



C.fullax, Form I., fig. 103 in front; fig. 104 outside; fig. 105 inside. 



Plate II. 



C. acutus, Form I., fig. 106 in front; fig. 108 outside. Var. A, Form. I., fig. 107 in front; fig. 

 109 outside. 

 Form II. (young 1.7 inch long), fig. 110 outside ; (2.7 inch long) fig. Ill outside. 

 Form IL (2.7 inch long) fig. 112 outside, imperfectly articulated. 

 Form II. (4.4 inch long), fig. 113 outside, not articulated. 



Ventre between the fourth legs of the female, fig. 114 ; the same in var. A, fig. 115. 

 Rostrum from above, fig. 116 ; var. A, fig. 117. 

 Epistoma, fig. 118; var. A, fig. 119. 



