7i THE ENTOMOLOGIST. 



6. The artificial yellow product has not yet been obtained in 

 a pure condition, but it may be so far purified as to exhibit 

 clearly all the general properties of the natural pigment. 



7. The natural pigment as prepared for analysis is shown to 

 be almost certainly a chemical individual. Its probable consti- 

 tution is discussed. 



8. It is shown that this yellow substance (denominated in 

 the paper " Lepidotic acid"), together with a closely allied red 

 substance, will account for all the chemical pigmentation of the 

 wing scales of the coloured Pieridae, though modifications may 

 be produced by superadded optical effects. The black pigment 

 found in the group is not dealt with in the paper. 



9. The described uric acid derivatives, though universal in 

 the Pieridae, are apparently confined to this group among the 

 Ehopalocera. This fact enables the interesting observation to 

 be made, that where a Pierid mimics an insect belonging to 

 another family, the pigments in the two cases are chemically 

 quite distinct. This is well seen in the genera Leptalis and 

 ]\IecJianitis respectively. 



10. The existence of pigments other than scale-pigments is 

 for the first time described ; substances, namely, which are 

 found between the wing membranes, and which, in certain genera, 

 are the basis of ornament. 



11. The fact that the scale-pigments are really the normal 

 excretory products of the animal used in ornament, is empha- 

 sised by the observation that the yellow Pierids, on emergence 

 from the chrysalis, are apt to void from the rectum a quantity 

 of uric acid coloured by a yellow substance which exactly 

 resembles the pigment of the wing. 



OYMNOPLEURUS ; CORRECTION OF NOMENCLATURE. 

 By John W. Shipp. 



Gymnopleukus, Illiger. 



Modestus, Lansberge, Notes, Leyden Mus. 8, p. 72, 1886. 



Peringueyi, mihi = modestus, Pery, Tr. Sth. Afr. Phil. Soc. 

 iv. p. 94, 1888. 



Peringueyi, Shipp (modestus, Pery nee Lansb.). — Nigro- 

 cyaneous, opace. Head granulose, a little broader than long, 

 rounded at base, produced angularly laterally, and with an acute 

 ridge on each side ; clypeus with the outer margin slightly 

 reflexed, deeply emarginated in the centre, which thus forms two 

 moderately acute teeth ; antennae black. Prothorax convex, once 

 and a half broader than long, with the sides rounded and slightly 

 angulated in the centre, marginated and finely granulose, 



