42 BULLETIN 143, UNITED STATES NATIONAL MUSEUM 



found in the first eleven species. This makes the group more or 

 less artificial. Rugulosa is included in the group quadriguttata 

 but the tubercles on the postero-lateral angles of the head are 

 much reduced and not easily seen when the head is in certain 

 positions. Likewise the species caneo is placed in the group 

 caneo because the tubercles on the postero-lateral angles of the 

 head are so rudimentary that they are seen with difficulty. There 

 is then a close connection between t^gulosa in the quadriguttata 

 group and the species of the caneo group." There is little doubt that 

 when the sexes are correlated that the groups quadrigiiffa.fa, castor^ 

 caneo, and monticola will need to be rearranged, since all are com- 

 posed entirely either of females or males. The group occidentalis 

 contains several species such as gorgon, leda aureola and its variety, 

 and sicheliana, which depart considerably from the general type of 

 the group. The group nogalensis contains two closely related species 

 combining characters of both the groups occidentalis and ohscura. 

 The group ohscura is quite distinct and composed of very closely 

 related species. The females in the group arenivaga are closely 

 related and with respect to the eyes very different from the other 

 members of the genus. The group subhyalina may represent the 

 males of the previous group. 



It should not be inferred that these groups are arranged in their 

 proper phylogenetic sequence although an effort has been made to 

 approach such an arrangement. Since only the species north of 

 Mexico have been studied, there are many elements lacking which 

 make it impossible to form a correct conception of the genus as 

 a whole. In addition to this there is the fact that a considerable 

 number of species are known only in one sex. The author does not 

 believe that any satisfactory phylogenetic study of the genus can 

 be made until these difficulties are overcome. Considerable advance 

 has been made, however, toward an arrangement which places closely 

 related species in proximity to one another, and this will surely 

 contribute toward a better understanding of the genus as well as 

 assist in the identification of material. 



HISTOUY AND DIAGNOSIS OP GENUS 



Genus DASYMUTILLA Ashmead 



Ephuta Say (in part), (not authors) Boston Journ. Nat. Hist., vol. 1, 

 1836, p. 297.— Andre, Gen. Ins., vol. 1, fasc. 11, 1903, p. 51. 



Sphaerophthalnw Blake (part), (not authors) Trans. Amer. Ent. Soc, 

 vol. 3, 1871, p. 232. 



DasymuUlla Ashmead, Journ. New York Ent. Soc, vol. 7, 1889, p. 57; 

 Can. Ent., vol. 36, 1904, p. 9.— Bradley, Trans. Amer. Ent, Soc, vol. 42, 

 1916, pp. 191, 312, 321.— RoHWER, Hymen. Conn., 1918, p. 623.— Mickel, 

 19th Kept. State Ent. Minn., 1923, p. 101. 



