April-June, 1920 Bulletin Brooklyn Entomological Society 69 



conformis, have hitherto been reported from western Massa- 

 chusetts. Rheumatohates rileyi, remarkable for its extreme 

 sexual dimorphism, is a notable addition to the New England 

 fauna, and this is the most northern point in its known distribu- 

 tion, if we except the doubtful Quebec record® of an immature 

 example found by de la Torre Bueno among the specimens de- 

 scribed as Halobatopsis beginii by Ashmead. In response to my 

 request for information regarding the labels attached to these 

 specimens, which are preserved in the National Museum, Mr. 

 Gibson most kindly sent them for examination and I find no 

 reason to suppose that the example of R. rileyi came from 

 Canada. One pin holds four nymphs of Metrobates hesperius, 

 the other a nymph of the same species and one of R. rileyi and 

 both bear hand written labels — "Nj. 27-7-96" — which I take to 

 refer to New Jersey. Another specimen from this series, which 

 I have not seen, bears the label " Sherbrooke, Can.," as described 

 by de la Torre Bueno, '^ but this is M. hesperius, and moreover 

 it is only to this that the original description refers or applies. 

 To the immature examples of M. hesperius sent from Canada 

 by the Abbe Begin and described by Ashmead^ as Halobatopsis 

 beginii, it is evident that there have been added, probably by 

 Ashmead himself, other materials from other localities, including 

 the specimen of R. rileyi, under the impression, of course, that 

 they were all conspecific. Only the specimen or specimens 

 labeled " Sherbrooke, Can.," can be regarded as type material of 

 Ashmead's unfortunate creation, and hence the citation^ of H. 

 beginii as a synonym (in part) of R. rileyi would seem hardly 

 justifiable. 



But to return to our association of water-striders. Visiting 

 the rapids again on September 29 with a class, we found three 

 of the species still active, though in reduced numbers, represented 

 by both adults and nymphs, but Gerris conformis and Rhagovelia 

 obesa had quite disappeared. Very likely these are of more deli- 

 cate constitution than the others and had been led to seek winter 



^ Gerrids of the Atlantic States, /. c, p. 251. 



'^ On Halobatopsis beginii Ashm. Can. Ent., 191 1, Vol. 43, pp. 226-228. 

 s A new water-bug from Canada. Can. Ent, 1897, Vol. 29, p. 56. 

 ^ Van Duzee's Catalogue, p. 431, doubtless following de la Torre Bueno, 

 op. cit., p. 228. 



