Insects. 7915 



and 150 specimens of Nyssia zonaiia; presented by Edwin Birchall, Esq. Tweke 

 specimens of Nonagria Bondii ; by Dr. Kuaggs. A series of Agrotis Ripa9 and a 

 series of Oporabia filigrammata ; by George Mawson, Esq. A pair of Agrotis Ripae 

 and a specimen of Xanthia gilvago ; by Mr. Henry Rogers. A series of Pbryganidse, 

 beautifully set, and all of them named in accordance with Mr. M'Lachlan's lately 

 printed list; by Percy C. Wormald, Esq. 



Mr. Stevens asked whetber the munificent present from Mr. Birchall did not 

 contain more specimens than were required for the collection. 



The Curator said that the large number was sent more especially for distribution, 

 every visitor to the cabinets on a Thursday evening being always invited to help 

 himself.— i:. N. 



Scales on the Wings of Lepidoptera. — I am led to believe, from a number of obser- 

 vations I have made, that scales of Lepidoptera differ in the number of membranes of 

 which they are formed, and in the granulations and striae which cover them. When 

 the scales are uninjured it is impossible to discover if they are composed of one 

 or more membranes, but as we often find some with damaged portions, these defective 

 scales permit us to study their formation. Scales covering the wings of Lepidoptera 

 seem to be composed of two or generally three membranes or lamellae placed one over 

 the other. It is always upon the upper membrane that the granulations composing 

 the colouring matter of the scale are found. The form of these granulations is gene- 

 rally pretty regular; they are rounded, and sometimes a little lengthened ; their num- 

 ber is^sometimes so considerable that the scale is entirely opaque. When strioe are 

 observed it is always upon the second lamella that they are placed. It would be ofteu 

 very diflBcult to assert with certainty the existence of these striae in a great number of 

 opaque scales,^did not the border, which on each side of the foot is generally transpa- 

 rent, permit their examination. Sometimes they are irregular, cou.sisting of cylin- 

 drical fragments placed on the membrane at unequal distances, but always parallel ; 

 sometimes they are perfectly regular. These are either small parallel cylinders, 

 clearly marked, and placed at equal distances, or equal parallel lines formed of gra- 

 nulations, like small round or oval pearls. It often happens that these striae are alter- 

 nately transparent and opaque. Sometimes there are small intervals divided into 

 small squares. When the intervals are greater, the squares which they form are found 

 transversely lengthened. On scales from P. Teucer, there are upon the striae series of 

 small pearls. It appears to me that in all the transparent scales upon which striae 

 are found without any appearance of granulation there are only two membranes. 

 There can be little doubt on this point, when regular strise, close to each other, are, so to 

 say, soldered together. But when, as on the large scales found on P. Telemachus, and 

 equally transparent, the striae have very little adherence with the membrane receiving 

 them, and are easily detached, the case is different. The stria seen, and which often 

 are over one hundred in each scale, are, when untouched, compos-ed of little cylinders 

 like harp strings, and when broken, like the same cords, they show the fractured ex- 

 tremities. Nothing in these scales at lirst proved to me the existence of a double 

 membrane, and the intervals between the striae, where they are wanting, never 

 show any trace of a tear. This may, however, arise from the adherence of the 

 two membranes. Fresh observations have convinced me that these two membranes 

 really do exist, but that the upper one, upon which are the striae, is so light that it is 



