170 [August, 



The forms with dentate mesosternum, limbnfn, ovafrr, and hipustu- 

 lata, are evidently ver}'^ closely allied, but separable without difficulty 

 when the entire hahitus is considered. In pale fresh specimens of 

 limhnta it may be possible to see faint traces of the black discal spot 

 on the elytra and the dark sutural stripe which has its most pro- 

 nounced expression in ovntn. In many pale specimens of ovatn, too, 

 one may detect a slight reddening of the free sides of the forehead 

 in the situation of the yellow spots proper to bipustulata, but this 

 circumstance hardly justifies the assumption that the two forms 

 intergrade, and whether these ]iale markings on the head in ovatn 

 are to be regarded as incipient or decadent there is no evidence to 

 show. At the present time limhnta is as far removed from ovata in 

 one direction as hipustiilnta is in the other, and although it has been 

 suggested that all three are still one and the same species, really 

 intergrade specimens are not so frequent as one might reasonably 

 expect if such were the case, at least I have quite failed to meet with 

 any. 



It was formerly supposed that limlnta was distinguished from 

 ovata by having the elytra more deeply punctured than the thorax, 

 but this distinction has since been dropped and I believe the difference 

 in question to be sexual. Certainly one finds specimens of limhata, 

 ovata and hipustulata in which the elytra are evidently more deeply 

 punctured than the thorax, and others in which the puncturation of 

 the thorax and elytra is practically of equal depth ; the former have 

 the second joint of the maxillary palpi more strongly developed, and 

 I suppose them to be males. The difference in the relative depth of 

 the puncturation of thorax and elytra in this sex is most marked in 

 limhata, less so in ovata and least of all in hifustidatn. 



A. limhatn projier appears to be less common in collections than 

 ovata, but this probably arises from the lack of attention to these 

 insects ; I find it not uncommon at Colesborne on the Inferior Oolite 

 at an elevation of about 700 feet, and I have a few old specimens 

 from different localities in Norfolk ; Dr. Sharp has sent me examples 

 from Scotland which he had separated as a variety from his variabilis, 

 from which it would appear that although his description of the latter 

 (Ent. Mo. Mag., vi, p. 255, 1870) might be taken to include both 

 limhata and ovata, yet in practice he regarded the Inst-named as more 

 his typical than variabilis. A. ovata may be found in small puddles of 

 the most temporary character as well as in more permanent waters, 

 and it is in my experience the most abundant of our species. A. 



