182 GEO. H. HORN, M. D. 



In separating species surface sculpture must be cautiously dealt with, 

 especially as there are often marked differences in this respect between 

 the sexes. 



I must again acknowledge my indebtedness to my friend Ulke, of 

 Washington, for his kindness in the loan of specimens, more particularly 

 for the types of forte and ohtusum. 



The species of Monilema are confined to the western and southwestern 

 regions of our country from western Kansas to Colorado, Utah, Texas, 

 New Mexico, Arizona, the extreme southeast of California and the 

 Peninsula of California, the regions in fact in which there are long periods 

 of drought, and in which Cactus is a marked feature of the vegetation. 

 Of their food-plants nothing. I believe, is known. 



The number of species known certainly to inhabit our fauna is now 

 twelve, with possibly one more (variolare) to be included. In the Bio- 

 logia Cent. Am.. Mr. H. W. Bates enumerates ten species from the re- 

 gions between our southern boundary and Panama, but it is greatly to be 

 regretted that he has remained content with tiieir mere enumeration as, 

 on the whole, the Mexican species of Monilema are about as unsatisfac- 

 torily described as any Cerambycidse with which I have had to deal. 



From the characters given in the preceding papers it is proposed to 

 divide our species in the following manner : 



A, — Scape of antennaR sub-mucronate inwards at tip. First joint of hind tarsus 

 as long or even longer than the next two and comparatively slender. 



Sub-genus Monilema. 



B.^Soape of antennre simple. First joint of liiiid tarsus not longer than the 

 next two and broad Sub-genus Collapteryx. 



Sub-genus Moiiileina. 



In addition to the above characters the following may be mentioned : 

 The first and second joints of the hind tarsi are glabrous at middle, the 

 second with a narrow spongy pubescent space each side, the third entirely 

 spongy pubescent. The anterior and middle tarsi have the first three 

 joints spongy pubescent beneath, the pubescence divided by a narrow 

 line. 



The two species belonging here are separated in the following manner : 



Thorax quadrate or a little wider than long, the sides with a feeble tubercle. 

 Elytra sparsely and regularly pimctured at basal lialf, wrinkled at apex, the sides 

 arcuately deflexed aiiniilatnin Say. 



Thorax cylindrical, usually longer than wide, without trace of spine or tubercle. 

 Elytra not conspicuously punctate, usually smooth but feebly shining, sometimes 

 with deep longitudinal wrinkles, the sides abruptly deflexed and obtusely mar- 

 gined near the base a|>prc»>a>uui Lee. 



