OF THE LARVA OF PYGÆRA BUCEPHALA. | | 187 
No. 35 in one specimen was divided into three at the upper end. 
No. 37 is sometimes å good deal expanded at its upper end, and sometimes divided 
into two. 
No. 38 in the same way is more or less divided at the upper end. 
No. 51 is more or less divided, the two main branches of which it consists being some- 
times united for a large proportion of their course, and sometimes, on the other hand, 
almost entirely separate. 
No. 52, which is usually single, was, on the contrary, in one specimen double. 
No.56. This series of muscles varies extremely. There are usually from 7 to 11 fascicles, 
but they were not alike in any two specimens I examined. 
No. 57 was double in the second specimen, and 
No. 58 in the fifth. 
Second Abdominal Segment.—The cases of variation in this muscle are almost the same 
as those already deseribed. 
No. 1 in the fourth specimen was completely double. 
No. 10 in the second specimen was double for the anterior half. In the fourth specimen 
10 and 11 were very small and united in front. In the ninth specimen 11 was double in 
front. 
Nos. 12, 13, 14, 15, 27, 28, 29, 30, 31, 32, 33 and 34 offered various differences of the same 
nature as those already mentioned; besides which, in the fourth specimen, 14 was much 
longer than 13 or 15. 
No. 26 was completely double in the second specimen. 
No. 38 was completely double in the fifth specimen; in which also 
Nos. 40 and 41 were united by their lower ends. 
No. 54 in the eighth specimen was completely double. ai 
First Abdominal Segment.—Nos. 12, 18, 14, 15, 27, 28, 29, 30, 31, 32, 33 and 34 differ as 
much as usual, ; 
Nos. 10 and 11 are sometimes united in front, sometimes they only converge and do 
not join. 
No. 18 in some specimens does not cover the fore end of 21. 
No. 37 in the fifth specimen is double. 2 ; 
Third Thoracic Segment.—Nos. 12, 13, 14 and 15 differ as in the above-mentioned 
segments; 29, 30 and 31, on the contrary, are much more regular. | 
No. 8 in the fifth specimen was completely double; in the sixth it was 
greater length, but united in front. 
No. 20, in the ninth specimen, was double in front. 
; Nos. 23 and 24 differed considerably in different specimens. T 
1, however, perhaps the most usual. 
No. 62. This småll muscle was in two cases entirely absent. 
No. 68 was double in two speci 
pecimens. ; ; e 
Nos, 59 and 60 are sometimes united; in the fourth specimen they were gar = 
“one si de, and had joined on the other. In the ninth specimen the iran en " 
VOL. XXII. 
double for the 
he arrangement figured 
