May, 1901.] 109 



species of the genus ; the frons at the vertex is about 



four times as wide as tlie posterior ocelli are apart, and 



is almost the same width opposite the lower fronto- 



orbital bristles, after which it rapidly narrows until 



just above the antenna it is not half as wide ; the 



face is still narrower, and the jowls very small. The 



frons is reddish-yellow about its centre, but the ocellar 



triangle and side stripes are greyish-white ; the face 



and jowls are whitish-grey, but the back of the head 



is a darker grey, more the colour of the pleurae ; the 



antennae are missing in the specimen from which I am Fig. -2.—//. atricornis, <5. 



describing. The head in profile is very deep but flat. 



Thorax slaty-grey, with faint dark stripes ; the pleurae, metanotum, and scu- 

 toUum arc all light slaty-grey. ' Length, 7 mm. 



This description and figure are made from a male in Bigot's col- 

 lection, labelled in Macquart's handwriting Heteromijzaatricornls,Mg.; 

 a female with a similar label is a Tephroclilamys, probably ruJiDentris. 



Two males taken by Mr. Verrall, one at Chippenham Fen near 

 here on September 29th, and the other in his own garden on December 

 2Sth, 1894, differ considerably from the above described specimen, and 

 may prove to be a distinct species. They are smaller (5 mm.), the face 

 is still narrower, and the jowls still smaller, antennae entirely black ; 

 the front facets of the eyes are decidedly dilated, a character that I do 

 not notice in the Macquartian specimen ; the stripes on the thorax 

 are fairly evident ; the stigma is longer, and the middle cross vein is 

 not opposite the middle of the stigma, but rather nearer the base. 



9 . Very closely resembling the female of rotundicornis, but I believe that it 

 may always be recognised by its face being distinctly narrower than the frons, and 

 by the vibrissse being closer together. The head in profile is deeper and flatter, while 

 the eyes are larger (t. e., deeper). It varies a good deal in size (4^ mm.— 6 mm.). 



I have seen four females taken in Scotland during July and 

 August, 1900, one by Mr. F. Jenkinson at Forres in Elgin, and three 

 by Col. Terbury at Qolspie in Sutherland, while T have studied two 

 females in Kowarz's collection from Marienbad, and five in Bigot's 

 collection, including his three original II. Delarouzei. 



H. atricornis was introduced as British by Curtis in his Gruide, 

 which record Brunetti and Verrall in 1890 tried to confirm, but 

 Brunetti probably, and Verrall certainly, from specimens of the next 

 species. Its larvse it would appear from the synonymy occur in the 

 excrement of bats. 



Desvoidy, in 1811, described a Thelida vespertiliovea taken in the 

 " Gx'otto d'Arcy-sur-Eure," which I believe to be identical with the 



M 



