Species of the American Genus Astylus. 339 



be recognized*. These hairy insects are found gregariously 

 on flowers in open places, and they bear a certain relation- 

 ship to the Palsearctic Henieopus, wanting the peculiar 

 structures in the legs of the males so conspicuous in nearly 

 all the members of the last-named genus. The two species 

 found in abundance by myself in Chiriqui in 1881-83 are still 

 the only known representatives of Astylus recorded from 

 north of the Isthmus of Panama. 



The forms represented in the British Museum collection 

 may be grouped by their structural characters or $ armature 

 thus :f — 



a. Metasternum without tubercles or dentiform pro- 

 cesses in tf . 

 a'. Wings fully developed. 



a 2 . Terminal abdominal segment with broad verti- 

 cal lamellae in rf , the segment itself transverse 

 on the ventral aspect ; sixth ventral segment 

 divided in 5 ; elytra more or less costate and 

 rugosely punctured : c? with bilobed tegmen 

 and strongly sinuate penis-sheath : species 



large, Chilean [Mecog-lossa, Sol.] Nos. 1, 2. 



b 2 . Terminal abdominal segment without lamelhe, 

 conical or narrowed posteriorly in c? ; sixth 

 ventral segment divided in § ; elytra not 

 costate : tf of A. -seafmaculutus with bilobed 

 tegmen and broad, obliquely truncate penis- 

 sheath Nos. 3, 4. 



c 2 . Terminal abdominal segment as in b' 2 ; sixth 

 ventral segment not divided in 5 • 

 a 3 . Elytra not constricted posteriorly in either 

 sex, at most obsoletely costate. 

 «*. Elytral apices rounded or obtuse in <3 5 , 

 or (A. vittatus) obliquely truncate in 9- 

 a 5 . $ with bilobed or emarginate tegmen 

 and acuminate penis-sheath, the inter- 

 mediate j oints of anterior tarsi angulate 

 at inner apical angle in A. antis and 

 splendidus. 

 a 6 . Anterior trochanters simple in c? .... Nos. 5-22. 

 b 6 . Anterior trochanters long and spini- 



form in $ No. 23. 



6 5 . J with bluntly rounded or truncated teg- 

 men and acuminate penis-sheath Nos. 2.4, 25. 



c 3 . c? with bilobed tegmen and apically 



dilated penis-sheath No. 26. 



* This article is catalogued in the ' Zoological Record ' for 1902, 

 p. 140, as " Notes on proposed n. spp." ; but the paper itself is not 

 analysed, and the new names are not given. 



t Males of A. hcematostictus, se.vpustulatm, conve.rus, and amabilis not 

 dissected, those of A. pallipes, imbricatus, and laticauda, and female of 

 A. forcipatus wanting. 



25* 



