Miscellaneous. 399 



PLACODUS ANDRIANI. 



To the Editors of the Annals of Natural History. 



Gentlemen, — In examining some fossil specimens recently trans- 

 mitted for sale, by M. Krantz of Berlin, to the British Museum, I 

 noticed certain structures in a part of the cranium of the Placodus 

 Andrianiy Agassiz, which convinced me that that triassic animal 

 belonged to the class of Reptiles, and not, as Count Miinster and 

 Prof. iVgassiz have described, to the class of Fishes. As some ac- 

 count of the teeth of Placodus is given in the chapter on the denti- 

 tion of Pycnodont Fishes, in my * Odontography ' (p. 73. pi. 30), 

 on the authority of those eminent palaeontologists, and before I had 

 had the opportunity of seeing original specimens, I lose no time in 

 correcting the error, as I trust to be able to prove it to be, when the 

 evidences of the Reptilian nature of Placodus are given in detail. 



I am. Gentlemen, 



Your obedient Servant. 

 British Museum, October 13, 1857. Richard Owen. 



A few Remarks on the Midge Fly which infests the Wheat. 

 By Jonathan Couch, Esq., F.L.S. &c. 



In the more eastern parts of the kingdom there has been long 

 known a little fly, the larva or maggot of which is highly injurious 

 to the ear of wheat, but, as far as my limited inquiries extend, it has 

 been little known in Cornwall, and it is only in the present year that 

 I have had an opportunity of examining it, or of hearing of its 

 ravages among us. It is called the wheat midge, or, according to its 

 more scientific name, Cecidomyia Tritici ; of very minute size, dark 

 colour, and slender shape ; the larva is of a decided yellow colour 

 and active habits. 



A long, and it may be supposed accurate account of this little pest 

 is to be found in a small work on the Blights of Wheat, published 

 by the Religious Tract Society ; and as the smallness of the price of 

 this volume renders it accessible to all who wish for information on 

 the subject, I will not repeat anything which is to be learnt there. 

 But in addition to this, an account of this midge-fly — for there are 

 several others of this genus — in its depredations on our staff of life, 

 was read before the meeting of the British Association, when it was 

 held at Plymouth, by an eminent naturalist ; and it is to notes made 

 at that meeting, added to the few observations collected in the month 

 of July in the present year, that I am desirous of soliciting attention 

 on the present occasion, to prepare our farmers for meeting this 

 plague, and, if possible, to prevent its obtaining residence among us. 



According to the little tract above referred to, this fly lays its 

 eggs in the grain in the month of June ; but some of them were 

 busy about the grains in the latter half of July ; and the succession 

 of development and hiding, which appears to take place in the larvse, 

 is presumptive proof that the depositing of eggs is not accomplished 

 m a very short space. At this time the grains of wheat had grown 



