OF THE LARVA OF PYGÆRA 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. 48, 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 under 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 under the 
upper side of 16. : 
No. 52 is small ; 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 end 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 from 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 under 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 which appear to 
represent those of the abdomen. There remain yet fifteen to be described. 
Nos. 59 and 60 rise under the fore end of 1, and pass upward and backward re 
dorsal line, where they are attached close to the anterior end of 9. 
No. 61 rises at the lower side of 60 and passes back parallel to that muscle, på rd 
. ås far, and at the same time dividing into two, so that its lower branch is attached close 
to the fore end of 12. — d the 
No. 62 rises close to the posterior end of 60 and passes ne Ys 
fore end of 4. In some specimens T could not find this muscle. 
D 
VOL. XXII. "T 
