74 [September, 



otherwise, as in festal 'lei la and erythriella. North America has, there- 

 fore, three known species of Ghrysocorys: G festaliella, Hb., G ery- 

 thriella, Clem., and Gfelicella, Wlsm. 



No specimens of the European genus Agdistis, nor of the North 

 American Scoptonoma occurred to our author. CiiemidopJwrus also 

 was not found. 



The genus Platyptilus was freely represented, no less than thir- 

 teen species being figured, of which one, P. Bertrami, is common both 

 to Europe and America ; the other twelve being, as far as is known, 

 exclusively American, and of these, ten are new to science. In the 

 whole of Europe only ten, or, at the most, eleven species have as yet 

 been discovered ; in both cases the Gonodactylus-gvoup, or that section 

 where the anterior-wings are light coloured with a well marked dark 

 triangle on the anterior costa, is far the most numerous. 



If we include P. grandis, Wlsm., as more nearly allied to P. 

 nemoralis than to P. Bertrami, eight species of this group are here 

 figured, and the distinctions between them are admirably shewn in the 

 illustrations ; the two of special interest are Platyptilus cardui* and 

 Platyptilus orthocarpi, "Wlsm. : we are so accustomed to look on the 

 Platyptili as having larvse which are internal feeders, passing their 

 lives in the stems of composite plants, that this would have been to 

 me, at least, part of the diagnosis of the genus, but in P. cardui, the 

 larva is gregarious in the heads of thistles, and in P. orthocarpi there 

 is a still wider divergence from the usual habit, the larva feeding on 

 the buds and flowers of Orthocarpus, one of the Scrophulariacea? ; P. 

 cardui, has another point of interest in the perfect insect approaching 

 so very closely to P. Zetterstedtii, one of the chief differences being that 

 the brown colour of the hind leg between the two pairs of spurs is 

 wider than in P. Zetterstedtii ; the habit of the larva is very distinct, 

 Zetterstedtii being an internal feeder, inhabiting the stems of Senecio 

 nemorensis (and, also, according to Heinemann, of Solidago virgaurece). 

 Of the other Platyptili, three are almost unicolorous ; one of which, 

 P. modestus, Wlsm., approaches the genus Ilimeseoptilus in a most 

 remarkable way, not in structure, but in the arrangement of the 

 spots and colouring. 



The question of identity of ochrodactylus and Bertrami, and of 

 their identity with the Bischoffii, of Zeller,f and of the cervinidactylus, 



* It seems to me imperatively necessary to alter these " bastard names," but would it not bi 

 advisable for the alteration to stand in the name of the describer? I should write this cardui 

 Riley dacti/lus), and not cardui Zeller. 



t All the Pterophori mentioned in Prof. Zeller's admirable paper, "Beitrage zur Kentniss de: 

 tioidamerikanischeu Nachtfalter," are alluded to in this paper. 



