22 HENRY F. CARTER. 



Spines ; hind metatarsi and second segments of all the legs with a pair of similar spines 

 at the extremities. Claws {cf. fig. 4, c) simple and equal, each with a short bristle 

 arising from the base. Abdomen dark brown, the margins of some of the tergites 

 narrowly grey, sparsely clothed with short brown hairs. Lamellae pale brown, 0-25 

 the length of the wing. Spermathecae two (a third very small, narrowly oval one is 

 often present), heavily chitinised, obovate, (47ya x 36/^<) ; a minute portion only of the 

 duct chitinised. 



The male was described by Weiss, who stated that it was uniformly darker in 

 colour than the female, and gave the following measurements :— Length of body, 

 1 -5 mm. ; length of antennae (barely), 0-5 mm. Judging by this author's description 

 and figures, it presents certain striking morphological differences from those males 

 which have been associated with species of Leptoconops {sens. str.). The eyes are said 

 to meet at a point above ; the palpal segments are depicted as subequal in length and 

 about three times as long as wide ; the fourth antennal segment almost twice as long 

 as the fifth, the fifth to twelfth short and broad, subequal, the last three segments 

 elongate, but the thirteenth almost equal in length to the fourteenth and fifteenth 

 taken together ; and the wings with reduced venation — the fourth vein being absent. 



Habitat. Egypt: Cairo, Behera, Wadi Natroun, Sakkara {Willcocks). Tunis: 

 Tabeditt {Weiss). 



Willcocks (1917) states that the species was first sent from Behera in March 1907, 

 and that it is common at certain seasons in Wadi Natroun, and in the autumn, when 

 the Nile is in flood, from Mena House to Sakkara. 



Leptoconops kerteszi var. peneti, Langeron. 



$. — Length of body, 1 • 5-1 • 8 mm. ; length of wing, 1 • 06 mm. ; length of antenna 

 (from figure), 0-45 mm. 



According to Langeron this variety differs from the specimens (type series) of 

 M. laurae in the Paris Museum principally in being larger, darker, and possessing more 

 numerous and stronger bristles and spines. In particular, he compares the develop- 

 ment and exact arrangement of the metatarsal spines in the two forms. He also 

 maintains that biological differences exist : the variety appears to persist later in the 

 year, occurs in a more southerly region, and at a much lower altitude than is recorded 

 by Weiss for the type form. M. laurae came from a mountainous region (altitude 

 500 metres), while the vav. peneti was found in the desert (mean altitude 30 metres), 

 in the marshes lying between the oases of El Hamma and the Shott Gharsa. 



In view of the individual variation in regard to size, and number and arrangement 

 of the metatarsal spines observed in a series of specimens of L. kerteszi, the distin- 

 guishing points cited by Langeron can scarcely be granted even varietal value ; but 

 in this author's excellent and detailed description of his specimens, mention is made 

 of a character which is of much greater importance, and which raises doubt regarding 

 its specific identity. The ungual formula is stated to be 0-1 — 0-1 — 0-1, and the 

 external claw of each leg is said to bear a small basal tooth. Such a condition occurs 

 in no other species of Leptoconops, and therefore, if Langeron's interpretation be correct, 

 the form should be easily recognised and would deserve specific rank. It should be 

 noted, however, that in some species the base of the claw is relatively broad and 

 projects slightly ventrally, so that, in certain positions, a minute basal tooth appears 

 to be present. 



Leptoconops kerteszi var. americanus, nov. 



$. — Length of body (three specimens), 1-75 mm. ; length of wing, 1-1 mm. ; 

 length of antenna, 0-32 mm. ; width of head, 0-30 mm. 



In spite of their widely distant places of origin I have been unable to find any 

 satisfactory characters for separating specimens from Utah (received through the 



