— I94-- 



This is the species which occurs in our lists as cribripenriis Thoni. 



S. lepidus Horn. L. c. 

 Length .38 in. =9.5 mm. Ilab. Arizona. 

 S. dolosus Horn. L. c. 



Length .27-. 42 in. =7-. 10.5 mm. Hab. Southwestern Texas. 

 S. debilis Horn. L. c. 



Length .30--. 36 in. =7. 5-9 mm. Hab. Utah. 



S. sobrius Newn (Elapli.) described erroneously from U. S. is a Mexican spe- 

 cies. 



CLYTINI. 



The characters separating this tribe are discussed in the "Classifica- 

 tion." It is sufficient to say here that they are all easily recognized by 

 their resemblance to a few abundant species represented in every cabinet. 



For the assistance of the student the various structures whose differ- 

 ences serve to separate the groups and genera are figured * Also the 

 frontal carinae of all the species of Xylolrechus. This feature is best seen 

 iiy holding the insect with the front uppermost. Then under a glass ol 

 \ery moderate power it will be seen as an elevated ridge, quite smooth, 

 starting below the eyes and running to a little past them, and dividing 

 at about the middle of its length into two lines diverging towards the 

 sides of the head. The species to which this description does not apply 

 are nitidus, 4-maculalus, and convergens. In these there are no diverging 

 lines and the division is only represented by an impressed space more 

 or less extensive. \v\ planif} om there is no carina at all and I have there- 

 fore placed it in Clylus. With this explanation 1 think the synopses will 

 be easy to follow. 



Whatever completeness this paper may have is largely due to the 

 kindness of my friends in allowing me to use their material and I take 

 great pleasure in returning my thanks to Dr. Horn, the National Muse- 

 um at Washington, and Messrs. Smith, Julich, Roberts, Ricksecker and 

 Welles and to Mr, Samuel Henshaw I am again indebted for a careful 

 revision itf the list of habitats. 



The genera are divided as follows. 

 Kjiimera of metathorax produced over the angles of'thc ist veniral segment, so as t<> 

 enclose the hind coxae externally; 

 Front short, intercoxal process of 1st ventral segment rounded.. ^//-ott/y Cyllenes. 



Front large, process acute Gronp Clyti. 



Epimera of metathorax not produced, ejiistcrna linear: front large, intercoxal pro 



cess acute, Group Anaglypti. 



Cyllenes. 

 Mesosternum usually convex in front, pro^ternum perpendicular at tip. 



Pronotum transversely excavated at sides near the base, Cyllenc. 



I'ronotum not excavated, Trichoxys. 



* riu' plati- will aiiompaiiy a luture number. 



