APHTHONA. 361 



Harold's catalogue ; many of these are very closely allied and difficult of determination, 

 the small size of the insects generally adding to the difficulty. Although it is generally 

 easy to distinguish Aphthona from Longitarsus on account of the long first tarsal joint 

 of the latter, it is much more difficult to separate certain species from the next genus — 

 Phyllotreta. In general it may be said that Aphthona is of a more convex and square 

 shape, that the elytra cover the pygidium, and that the frontal tubercles are distinct. 

 Europe seems to have furnished most of the species described as yet, but the genus is 

 represented in nearly all parts of the world. Central America does not seem to possess 

 many species, and but two or three have up to the present been described from, that 

 country. 



1. Aphthona deyrollei. 



Aphthona deyrollei, Baly; Trans. Ent. Soc. 1877, iv. p. 296 \ 

 Eab. Mexico, Teapa l (coll. Baly). 



The general colour of the upper surface of this species, the type of which 1 have 

 before me, is pale fulvous, with a slight metallic greenish gloss, which it has in 

 common with several other Central- American forms belonging to Aphthona. In the 

 present species the antennae, which are long and slender, have three, or sometimes four, 

 of the intermediate joints piceous, the rest fulvous, by which, in connexion with the 

 very finely punctate-striate elytra, the insect may be recognized ; it has not been met 

 with by Mr. Champion or Herr Hoge, but other very closely allied species are 

 before me. 



2. Aphthona diversa. (Tab. XXI. fig. 20.) 



Aphthona diversa, Baly, Trans. Ent. Soc. 1877, iv. p. 297 \ 



Hah. Mexico, Teapa 1 (coll. Baly) ; Guatemala, near the city, San Geronima (Cham- 

 pion) ; Panama, Caldera in Chiriqui (Champion). 



In this species the elytra are metallic blue, and the vertex of the head piceous, with 

 a slight metallic gloss. Mr. Baly says, in his description, that the basal margin of the 

 thorax is edged with black at the sides, but neither in the type, which is before me, 

 nor in the other specimens contained in Mr. Baly's collection, can I discover any trace 

 of a black margin. Some of the Guatemalan specimens obtained by Mr. Champion, 

 and which I cannot separate from the type, have a slight metallic gloss on the thorax, 

 and the elytra of a more obscure bluish colour; other slight differences in shape are 

 also visible in these examples, which are a little more robust and convex than the type ; 

 but I think these differences are but attributable to variation of locality. The speci- 

 mens obtained in the State of Panama are more robust, the antennae longer, and 

 the punctuation of the elytra more finely impressed, the colour of the latter being also 



biol. centk.-amek., Coleopt., Vol. VI. Pt. 1, May 1885. 3 a 



