OF THE LARVA OF PYG^RA BUCEPHALA. 179 



No. 36 is absent, as in the first abdominal segment. 



Nos. 37 and 38 in the thoracic segments pass more forward, so that they are situated at 

 the hinder end of a segment rather than at the front. 



No. 39 is absent, as there are no spiracles in the two posterior thoracic segments. 



No. 40 is double behind. No. 41 is parallel to 40, but not more than half as long. 



No. 42 rises at the lower side of the fore end of 41, and passes upward and backward 

 about as far as 40. 



Nos. 43, 44 and 45 are absent. 



No. 46 rises under 17, just behind 38, and passes straight upward, and divides at the 

 same time into two diverging branches, both of which are attached to the skin under 7. 



Nos. 47 and 48 are not present. 



No. 49 much resembles 46, in front of which it is situated. It is however more deeply 

 forked and is shorter, its lower end not passing so far down. It also passes inside 67, 

 while 46 lies outside that muscle. 



No. 50 rises imder the posterior end of 7 by a double head, and passes forward and 

 downward to be inserted under the middle of 16. 



No. 51. This muscle rises immediately behind the upper end of the hinder branch of 46 

 and passes straight down, diverging however a little from 46, to be attached iinder the 

 upper side of 16. 



No. 52 is smaU ; it rises at the lower end of 50 and passes to the hinder side of the lower 

 end of 51. 



No. 53 is absent. 



No. 54 rises just behind the lower end of 51 and passes upward, going at the same time 

 under 51, and being attached under the middle of 46. 



No. 55 rises close to the lower end of the preceding, and passes upward and backward 

 about as far as the posterior Aid of 7. 



No. 56 differs very materially from the series of muscles so marked in the abdominal 

 segments. It is here double. The two fascicles rise just in front of and rather above 57, 

 and passing downward and forward, at the same time diverging fi-om one another, are in- 

 serted opposite the posterior end of the muscles 23, 24 and 25, belonging to the opposite 

 side. 



Nos. 57 and 58 are represented by three small muscles which rise imder 25 at a little 

 distance apart and pass forward, converging at the same time, and are inserted into the 

 legs. They frequently coalesce so as to form only one muscle. 



We have now completed the muscles in the third thoracic segment wliich appear to 

 represent those of the abdomen. There remain yet fifteen to be described. 



Nos. 59 and 60 rise imder the fore end of 1, and pass upward and backward to the 

 dorsal line, where they are attached close to the anterior end of 9. 



No. 61 rises at the lower side of 60 and passes Ijack parallel to that muscle, but t^vice 

 as far, and at the same time dividing into two, so that its lower branch is attached close 

 to the fore end of 12. 



No. 62 rises close to the posterior end of 60 and passes for^^'ard and do^^'nwal•d to the 

 fore end of 4. In some specimens I could not find this muscle. 



VOL. XXII. 2 B 



