June, igi6 Bulletin of the Brooklyn Entomological Society 67 



than in the male, especially in fitckii, which species has a very 

 large hypopygium, the males have also 2 small, round, raised 

 areas transversely situated near the middle of last segment. 



In both species of Promachus I find, in addition to the spiracles, 

 2 very distictly elevated rugose areas on the anterior margin of 

 the mesothorax, one on each side of the dorso-median line. In 

 other AsiHdse which I have examined the corresponding areas are 

 not appreciably distinguished either by elevation or. rugosity. 



The following diagnosis will serve to separate fitchii and verte- 

 bratus, and should be used at caption 9 in my key to the species . 

 in the paper already mentioned. 



Lateral cephalic process consisting of 3 simple thorns, the upper one 

 strongest; the last 5-8 thorns on lateral extremities of transverse 

 armature of abdominal segments 2-7 stout, flattened, and rather 

 wedge-shaped, their bases fused so that the whole appears as a flap- 

 like process with a deeply serrate posterior margin ; eighth ventral 

 abdominal segment of male with 2 thorns ; average length 25 mm. 



vertebratus. 



Lateral cephalic process consisting of 3 thorns, the upper one bifid or 

 sometimes duplicated, so that the process appears quadrispinose, the 

 middle thorn generally strongest; the last 5-6 thorns on lateral ex- 

 tremities of transverse armature of abdominal segments 2-7 very 

 slender, their bases distinctly swollen but not fused ; eighth ventral 

 abdominal segment of male with 4 thorns; average length 21 mm. 



fitchii. 



In addition to the above, fitchii differs from vertebratus as 

 follows : the upper cephalic thorns are shorter and stouter and 

 the distance between them is greater, at apices exceeding the 

 length of a thorn, whereas in vertebratus it is distinctly less than 

 the same ; the wart-Hke protuberance on wing in longitudinal line 

 with the abdominal spiracles is small, rugose, and without an 

 outstanding sharp ridge, while in vertebratus it is rather large 

 and has a sharp ridge which is directed slightly upward ; the 

 abdominal armature is weaker, especially on lateral areas, where 

 it is not, as in vertebratus, noticeably stronger than the armature 

 of the post-spiracular area ; the transverse armature of the 

 seventh dorsal segment consists of long thorns only, the small 

 ones that occur between these in vertebratus being absent ; the 

 apical armature consists of an upwardly directed thorn, much 

 shorter and broader than that in vertebratus, and a very small 

 one at its base. 



