26 PROCEEDINGS OF THE ACADEMY OF [1885. 



An Example of SamiaCecropia having a Fifth Aborted Wing. — 

 T have lately received from Mr. Ph. Laurent, of Philadelphia, 

 an example of Samia Cecropia, bred by him from a cocoon, having 

 an aborted, or rather the portion of a third primary. It is a male 

 of the ordinary size, expanding about 5| inches, and is one of 

 those smoky varieties in which the red portion of the transverse 

 bands on wings is very much narrowed. The right primary and 

 both secondaries are normal in shape and marking. The left 

 primary is in length from base to apex exactly the same as is the 

 right ; but in width from inner angle across to the costa, it is -j 3 ff 

 inch less ; the markings are the same, allowing for a little con- 

 densing owing to the difference in the width. The venation is 

 normal in all wings ; the left primary is also somewhat narrower 

 at the base where it joins the body ; the inner margin is in exact 

 line with that of its fellow, thus causing the wing at costa, where 

 it joins the thorax, to be further in from the collar and head than 

 its opposite. 



The third primary, or rather portion of a primary, emerges 

 from the side of the collar, and consists mainty of the costal and 

 subcostal nervures, a small part of the median nervure, and a 

 strip of wing about a quarter of an inch wide ; but the latter was 

 much curled and twisted in drying, and does not show this width 

 fully. Its length is about two-thirds that of the normal wing 

 with which it runs parallel, but it is in no way visibly connected 

 therewith. 



This form of monstrosity is apparently of exceedingly great 

 rarity. I have heard of only three other instances — those 

 recorded by Prof. Westwood in the Trans. Ent. Soc. Lond., 

 1879, pp. 220, 221, in which three diurnals are described, each 

 possessing a third aborted right-hand secondary; In one of 

 them, an example of Gonepteryx Bhamni, the normal right wing 

 is much less than the left, the same with the second example, a 

 Vanessa Urticse, leading to the conclusion in those cases as with 

 the Cecropia, that the abnormal wing was produced at the expense 

 of the normal. 



In the two cases just cited, the extra wing is joined at the base 

 of the costa to the proper wing; in the third case mentioned by 

 Prof. Westwood, it is apparent^ a streak or strip, as it were, 

 on the inferior surface of right secondary, distinguished from the 



