294 Mr. W. Wanou on new 



division is presented. Tlie enamel-organs of tlie molars are 

 tlierefore here also in connexion with an epithelial cord, 

 which is prolonged laterally on the inside of the dental rudi- 

 ments ; we have in this case also the representation of the 

 origin of treth of tlie first dentition before us, although rudi- 

 ments of the second dentition are not distinctly formed. The 

 epithelial cord terminates further back in a knobbed swelling, 

 which is perhaps the earliest rudiment of the fourth molar. 



Although the facts may yet be considerably amplified by 

 further investigations, nevertheless I consider that I may 

 already maintain that embryology furnishes no support for 

 attributing t!ie first two so-called molars of the upper jaw and 

 the first three similar teeth of the lower jaw to another den- 

 tition than tiiat to which are attributed the rest of the teeth 

 wiiich lie in front of them. There are no molars at all, but 

 premolars. The dentition of Dideljihys which cuts the gum 

 and is permanent therefore belongs (with the exception of 

 the last molars, which appear at a late stage of devcloprntiut) 

 to the first series, or tlie milk-dentition. 



XLV. — Descriptions of new Genera and Species of Pyralidaj 

 contained in the British- Museum Collection. By W. 

 Wakren, M.A., F.E.S. 



[Continued from p. 170.] 



MiCHACTiS, gen. nov. 



A subdivision of liotijs. Characterizt-d by the j)rescuce of 

 a small raised linear dash close to the base immediately 

 beneath the intcrno-median vein of the fore wing of the male. 

 The females are always larger and generally [)aler than the 

 males. 



Ty[)C J/. nuhil((lis, Hub. [Pijralis), 



Micrac'.is sanffuinealisj sp. n. 



Fore wii'.g deep yellow, more or less thickly suffused with 

 dull red, the costa throughout decjier ; lines themselves red- 

 dish ; first curved outwardly, jiroceded by a yellowish Sj)ace, 

 the basal area up io it suffusedly reddish ; central space 

 between the two lines thickly sufi'useil with red, the two stig- 

 mata dec])cr ; second line, slightly serrated, forms a distinct 



