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MR. LUBBOCK ON THE CUTANEOUS MUSCLES 



instead of lying at the side of 60, was inserted under, that is to say, at tlie outer side of 

 it. In two specimens there was a small muscle lying at the dorsal side of 59. 

 No. 61 is sometimes simple heliind, sometimes divided. 



I now proceed to compare the muscles of Fygcera with those of C'ossiis ligniperda, as 

 described by Lyonet, and of one or two other insects which I have more or less com- 

 pletely dissected. 



The following Tal)le shows the letters and numbers used for the corresponding muscles 

 in the abdomen : — 



Thus, with very few exceptions, every muscle of the third abdominal segment in Fygcera 

 can be referred to its homologue in Cossus. 



There are, however, some few differences : B in Cossus is only as long as the segment, 

 as is also the case in the larva of Pontia rapi ; while 2, the corresponding muscle in Fygeera, 

 has united with the same muscle of the two preceding segments, — the three together 

 forming only one muscle as long as the first three abdominal segments. 



Again, G shows traces of subdivision, and is covered in part by F, while 5 is single, and 

 lies on the dorsal side of 8. I also is tre1)le, while 9 is single. L is treble, while 10 and 

 11 only form two muscles ; on the other hand, Q is only treble, while the series from 12 

 to 15 is quadruple. 



e crosses OYev ff, so as to cover it behind instead of lying at the side of it. k does not 

 seem to be present in the third abdominal or any of the posterior segments of Fygcera, 

 and only makes its appearance in the second abdominal segment. 



There seem to be three fascicles, marked t, to correspond to 33 and 34 ; and 35 and 86, 

 which are marked 0, are represented by several fascicles. 



First and Second Abdominal Segments. — In these segments there are no further differ- 

 ences of importance. 35 and 36, however, which in Fygcera are reduced to a single 

 muscle, continue in Cossus compound as before. 



Nos. 46, 47, 48, 49 and 50 appear all to be repi'esented by (5. 



ffand e resemble 19 and 20 more than in the posterior segments. 



In the thoracic segments it is much more difficult to compare the muscles of Cossus and 

 Fygcera ; indeed, after devoting a good deal of time and thought to it, I have been obliged 



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