[144] REPOET UNITED STATES ENTOMOLOGICAL COMMISSION. 



variably short and broad, and, vrhether C. aUanis be only a smaller and short-winged 

 variety or not, it seems to me that the forms commonly known as C. «prcfMS and C 

 atlanis should receive distinct names, both common and scientific, for the sake of con- 

 venience ; and I am, from a study of the material thus far examined, inclined to con- 

 sider the two forms as specifically distinct. Theoretically I regard atlanis^ being the 

 more widely diffused form, as probably the parent stock from which C.-spretus has sepa- 

 rated. That C. atlanis is a variety of C. femur-ruhruvi is not, I think, warranted by any 

 facts that J have observed, though both forms may have originated from a common 

 ancestor. 



Caloptenus femur-nibmm. — This species occurs in abundance at Shasta Valley and 

 Portland, Oreg., C atlanis being associated with it, but much less abundant, as in 

 the Atlantic States. I also received it from near San Francisco through Mr. Henry 

 Edwards, and from Salt Lake, Utah, through Mr. Barfoot. I can, after careful com- 

 parison, see no difference in size, length of wings, and the form of the anal cerci be- 

 tween the Pacific coast and Atlantic coast or Utah specimens. In one C. femur-ruhruniy 

 from Portland, Oreg., there is a deep, well-marked notch in the tip of the male ab- 

 domen. In several instances I have seen a faint notch in Massachusetts specimens ; 

 on the other hand the male tip in C. atlanis is very slightly notched ; sometimes it is 

 almost obsolete. The male of C. femur-rubrum is not only easily separated from the 

 male atlanis by the rounded, entire tip of the abdomen, but also by the very different 

 form of the anal cerci, which are triangular and produced at the end. 



As regards the length of wing in C. atlanis or in C. femur-rubrum, it has for years 

 been known to me that many C. femur-ruhrum have short wings as well as long wing& 

 I find this to be the case with atlanis. In a <? atlanis from Amherst, Mass., the wings 

 are shorter than in C. femur-rubrum from Essex County, Mass. One ,? atlanis from 

 Massachusetts and one $ from Illinois had wings of the same length as in C. femur- 

 rubrum from Massachusetts. In a ^ atlanis from Shasta Valley and C femur-rubrum 

 the wings are of the same length. The wings in the Lake Tahoe C atlanis are much 

 shorter than in San Francisco or Massachusetts femur-rubrum. From these examples, 

 selected at random, I infer that there are short and long winged C. atlanis as well as 

 C. femur-rubrum. 



A singular variety of C. atlanis I captured at Amherst, Mass., this year, in October, 

 has curiously forked anal cerci, the males measuring (including the folded wings) 1 

 nch or 20"^'^, the wings in one case being slightly shorter than the abdomen. 



