106 
W. !■'. rURCELL. 
1 ‘epresented as cut along the groove {gr.) in figs. 8a-8d, and along the 
deepest part of the pulmonary sae (pulm. s.) in figs. 8f and 8g. 
Figs. 8a-8h. — (Zeiss oil iin., II, hot ale. suhl.) Longitudinal 
sections through the first al>doniinal appendage, of which fig. 8 is a 
reconstruction. Figs. 8a-8e pass through the medial and 8p-8h 
through the lateral halves of the appendage, and their i^ositions are 
indicated in fig. 8 ; ep., ejpithelium (belonging to somite 9) behind the 
first al)dominal appendage. 
PLATE 3. 
Embryology of Attus floricola. 
[Longitudinal sections are cut parallel to the principal axis (pr. ax. 
in figs. 1-3) of the appendage.] 
Figs. 9 and 10. — (Zeiss oil im., II, hot. ale. siahl.) Longitudinal 
sections (from different embryos) through the medial region of the first 
aI)dominal appendage at the commencement (fig. 9) and the end (fig. 10) 
of the stage with two pulmonaiy furrows ; ep., epithelium (belonging to 
somite 9) behind first appendage. 
Fig. II. — (Zeiss oil. im., II, hot ale. suhl.) Section through the 
medial region of the first abdominal appendage at about the com- 
mencement of the 3-furrow stage, cut at a slight inclination to the 
longitudinal axis of the appendage. 
Fig. 12. — (Zeiss ^ oil im., II, hot ale. suhl.) Longitudinal section 
through tlie lateral region of the first al>dominal appendage at the stage 
with four to five pulmonary furrows. 
Figs. 13-13b. — (Zeiss oil im., II, hot ale. suhl.) Transvei'se 
sections cut parallel to the anterior side of the first abdominal appen- 
dage at a stage with at least five well-develojoed pulmonary furrows, 
fig. 13 being the second, 13a the fifth, and 13b the eighth section from 
the posterior side of the ajjpendage (13 and 13a ai’e in outline and show 
ectodermal tissue only), sp. The primitive sj^iracle ; s. 1-s. 5, the five 
oldest saccules. 
Fig. 14. — Sketch of first alKlominal appendage of the right side at 
tlie stage with two pulmonary furrows, from a wax reconstruction, seen 
from behind and distally. 
Fig. 15. — (Zeiss oil im., II, hot ale. suhl.) Sagittal section (cut 
parallel to the median plane of the embryo, c.f. fig. 2) thi’ough the first 
abdominal appendage at the commencement of the stage with four 
pulmonary furrows (slightly later than fig. 2). 
