THK CANADIAN ENTOMOLOGIST. 311 



The practice has become prevalent of erecting gene? a not only on 

 trivial character?, but hastily and without proper comparison of allied 

 forms. For example, Stetkofiiyia, Theobald, a genus of Anophelines, has 

 been founded upon the so called mammillated prolhoracic lobes. We 

 have received authentic specimens of this species through the kindness of 

 Dr. Oswaldo Cruz, and find that, firstly, Theobald's picture gives an 

 altogether exaggerated idea of the structure, while, secondly, the same 

 structure occurs in all the other species of Anopheles that we have 

 examined. 



The scales on the metanotum are another character which has given 

 rise to error. The subfamily Trichoprosoponina has been founded upon 

 the presence of scales together with setae on the metanotum. The genus 

 Sabethes ( sensu Theobaldi), however, which has the metanotum densely 

 covered with scales in all the species which we have examined, is excluded. 

 The presence or absence of scales is of no fundamental importance; their 

 value is far less than that of the setae. Practically their use is confusing, 

 since in indifferent specimens they may be entirely rubbed off, leaving no 

 trace, and causing the student to misidentify his material, if not to actually 

 found a new genus. 



We have elsewhere called attention to the fact that the so-called 

 ciliate legs do not form a tangible character for generic separation. In 

 the forms Qi Janthinosoma we find all degrees of intergradation between 

 strongly "ciliate" hmd legs and those with the vestiture smooth. A 

 similar condition obtains in the species of Psorophora. Even mere 

 striking cases may be found in the group Sabethini ; the genus 

 Lesttcocanipa includes species with strongly " ciliate " legs, and with 

 perfectly normal ones. The genus T?'ichoprosopon, Theob , was founded 

 upon the species nivipes^ Theob., in which the legs are not "ciliate"; 

 Dr. Lutz has described a species from Brazil (splendens) with strongly 

 " ciliate " legs, but has wisely refrained from proposing a new generic 

 term. 



Another character made use of by Theobald in his recent work 

 proves to be untenable for generic separation. We refer to the so-called 

 spiny front margin of the wings. This consists of a series of more or less 

 spine-like scales inserted on the front margin of the wing. These may be 

 more or less conspicuous, not only from differences in development, but 

 according to the degree in which these scales are overlapped by the other 



