Insects. 8057 



and, as I have been the cause of this error, it is necessary to add some 



explanation of its origin. When I was in Paris two years ago M. 



Fairmaire very kindly gave me a pair of Ptinellae, supposing them to 



be specimens of his own P. denticollis, both of which have since been 



proved to be P. aptera. In justice to M. Fairmaire I must say that 



they were taken from his boxes by candle-light, and had he anticipated 



the purpose to which they have been applied, he would doubtless have 



been more careful in his selection. With these specimens all the 



British examples have been compared, and of course wrongly named. 



A few weeks ago M. Fairmaire gave me other, and this time authentic, 



specimens of P. denticollis, as widely different from the former as any 



two species of the genus. The true P. denticollis has occurred, though 



rarely, in England ; all the insects at present bearing that name in 



British collections are P. aptera. As that species was fist described 



by M. Guerin, there can be no doubt but that the French specimens 



represent the true P. aptera, though I cannot suppose that the species 



figured by Gillmeister under that name is identical with M. Guerin's 



insect; his description, his figure, and the natural size given in his 



plate, all combine to make it the largest of the apterous species, while 



m truth it is the smallest of all except P. angustula ; indeed his figure 



and description appear more applicable to the apterous variety of P. 



ratisbonensis than to any other species. 



The mistake I have just mentioned is the only one of general im- 

 portance, though others have occurred, and have been in most instances 

 already corrected. It could hardly be wondered at, when entering 

 upon ground previously untrod by any British entomologist,* without 

 a single type to guide me, and nothing but descriptions to refer to, 

 that I should occasionally fall into a mistake of identity among insects 

 so obscure and so little known as these. But I have lately spent a con- 

 siderable time in Paris in investigating their nomenclature, and have 

 compared all the British species of Trichopterygidje with those con- 

 tained in the collection of M. Aube. Through the kind assistance of 

 that gentleman, MM. Fairmaire and Reiche I have, I hope, reduced 

 the names of the whole family to a strict uniformity with those in use 

 on the Continent. 



The Trichopterygidae in the magnificent collection of M. Aube were 

 formerly examined and named by Gillmeister, and may justly be con- 

 sidered as the types of that author. 



* lu April, 1858, I announced the capture of Ptinella britannica, the first of the 

 genus ever met with in this country (vide Z.ol. 6032). It is still unique, and totally 

 distinct from any other known species. 



VOL. XX. 2 H 



