REHN AND HEBARD 235 



We have observed that the antennal length is decidedly greater 

 in some species than in others, but accurate measurements of 

 the same are very difficult and these delicate organs are found to 

 be incomplete in so many cases that we have deemed it best to 

 omit discussions of the same. 



Efforts to include all the known species in the keys of Redten- 

 bacher/- Saussure and Pictet/^ Karny" and Bruner'-^ without 

 having material of many of the species for examination, com- 

 bined with the employment of such usually worthless characters 

 xis tegminal and ovipositor length — given with scarcely any re- 

 gard to the extremes of variation and in complete disregard of 

 the probabilit}' of macropterism and brachypterism appearing in 

 the same species — has made these keys virtually worthless and in 

 many cases misleading in the extreme. 



The following described species do not appear to he included in 

 the material before us. In future studies with the present paper 

 they must be carefully considered, but at present we feel only 

 justified in giving the following brief remarks resulting from study 

 of the various original descriptions and in tabulating these species 

 from the same source as far as possible on pages 238 and 239. 



caizanum 



1897. [Xiphidium] caizanum Giglio-Tos, Boll. Mus. Zool. Anat. comp. Univ- 

 Torino, xii, no. 302, p. 42. [1 cf : Caiza, Ecuador.] 



The form of the cerci and subgenital plate is apparentl}^ differ- 

 ent from any other known American species. The species very 

 possibly belongs to an undescribed subgenus, apparently between 

 the subgenera DiceUura and Xiphidion. 



exitiosum 



1901. Xiphidium exitiosum McNeill, Proc. Wash. Acad. Sci., iii, p. 501, 

 fig. 42. [2 cf , 3 9 , 3 juv.: Indefatigable Island, Galapagos Islands.) 



This species is so poorly described and the rough sketchy out- 

 line figure of the female so unsatisfactory, that we can Init state 

 that the species may be related to C. cincrcus. 



•2 Verb. k.-k. zool.-bot. Gesell, W'ieii, .\li, pp. 49.')-499, (1891). 

 " Biol. Cent.-Amer., Orth. i, pi). 396-397, (1S9S). 

 " Abh. k.-k. zool.-bot. Gesell. Wien, xli, pp. 85-94, (1907). 

 '5 Ann. Carneg. Mus., i.x, pp. 372-374, (June 1815). 



TRANS. AM. ENT. SOC, XLI. 



