74 [April, 



here the ajipendages, though by no means small, are far more 

 moderate in size — those of concomitclla stand out as considerably 

 the lai'gest, and an ordinary ])ocket lens could at once pick out the 

 males of this species by this character alone. The chief points of 

 differentiation come under three heads, namely, the amount of asym- 

 metry, the form of the claspers, and the form of the spines. The 

 asymmetry resides mainly in the spines, it is most conspicuous in 

 concomitelln, where the body of the right spine is reduced to a tiny 

 knob ; almost equally pronounced in mespilella and pyrivorella, more 

 moderate in hlancardella and oxijacanthcs, and well on the way to 

 extinction in sorhi. To what extent it prevails in the continental 

 cydoniella I am unable to say, as I bungled over the dissection and 

 only obtained the left clasper. As a rule the claspers themselves 

 exhibit but little asymmetry, and when they do, it is the breadth 

 of the organ alone that is affected ; in mespilella and furivorella, 

 however, the asymmetry is conspicuous, the left clasper being con- 

 siderably broader than the right. 



The claspers are simple, and have no trace of the formidable 

 teeth presented by spinicoleUa and cerasicolella, but instead their 

 outer ends are furnished on the inner face with a thick mat of stoutish 

 bristles, which it has not been thought necessary to repi'esent. There 

 is considerable diversity in their shape, and as this can only be pro- 

 perly appreciated when the organs are seen in full, and the figures 

 represent them in profile, I will briefly describe the difference. In 

 mespilella and pyrivorella they are unusually stout, very wide at the 

 base, especially the left one, diminish rather abruptly about the 

 middle, and thence onward to the end remain of the same size ; they 

 are essentially clumsy looking. In sorbi they are more elegant and 

 much more slender, widening out gradually towards the distal end, 

 and resembling closely the funguses known as Clavarice. In concomi- 

 tella they are particularly slender, distinctly narrowest about the 

 middle, thence gradually widening, forwards to the distal end and 

 backwards to the foot. In hlancardella they are slightly dilated at 

 the distal end, otherwise of uniform width down to the foot. In 

 oxyacantJicB on the other hand they are pointed at the end and 

 widen by degrees backwards to the foot. 



The spines (c) are hollow chitinous bodies like the claspers, but 

 of denser material, and are crowned at the apex with a solid spur, 

 they afford excellent characters, and have this advantage over the 

 more yielding claspers, that though they may be easily broken, they 

 are less liable to be pressed out of shape — as the figures display 



