1967] 
MacLeod & Adams — Berothidae 
263 
(“penisfilum”) which the mediuncus undergoes in some genera of 
both the Berothidae and Mantispidae. Since this modification seems 
to occur sporadically only among the more specialized members of 
these families, it seems more likely that this similarity is also the 
result of parallel specializations from the more generalized type. 
Additional close similarities occur between generalized berothids 
and the Mantispidae in the wide connection between the genital 
chamber and bursa; in the rather long, narrow spermathecal duct; 
and in the coiled tubular shape of the spermatheca which lacks prom- 
inent dilations. MacLeod (1964) has pointed out additional similari- 
ties between these two families on the basis of the structure of the 
larval head. 
The very mantispid-like condition of the forelegs of the Rhachi- 
berothinae suggests that the Mantispidae may have taken their origin 
directly from members of this group of berothids. However, such 
features of Rhachiberotha and Mucroberotha as the fusion of the 
9th abdominal tergite and ectoprocts, the presence of hypocaudae, the 
loss of the recurrent humeral vein, and the development of the very 
characteristic marginal forking of CuA and the reduction of CuP 
in the hindwing are all specializations characteristic of the higher 
Berothidae. Since the great majority of Mantispidae lack these 
peculiarities, it seems quite likely that these specializations were also 
lacking in their direct ancestors and that these ancstors must be 
sought in some other group of berothids or near berothids. 
It must be noted, however, that similar specializations occur, with 
a mosaic distribution, among certain genera of the Platymantispinae. 
Thus a partial or complete fusion of the 9th abdominal tergite and 
ectoprocts occurs in Plega and Trichoscelia (— Symphrasis ) ; small 
tubercles, probably homologous to hypocaudae, are present in Drepani- 
cus; and a reduction or loss of CuP in the hindwing is found in 
Drepanicus and Gerstaeckerella, while this latter genus shows the 
loss of the recurrent humeral vein as well. With the exception of the 
hypocaudae-l’ke tubercles of Drepanicus , these are characters involv- 
ing the fusion or loss of structures and their sporadic occurrence in 
the Platymanfispinae is very likely the result of parallel evolution. 
The structural heterogeneity of this subfamily does, however, sug- 
gest that a similar variability may also have once been present in 
the Rhachiberothinae, so that the possibility cannot yet be ruled out 
that the primitive Mantispidae did evolve from some unknown 
rhachiberothine which lacked the specializations of the more advanced 
Berothidae noted above. 
