Segments. 
1 |Chelicers. 
2 |\Chele. 
6 |Walking legs. 
Appendages. 
3 |Walking legs. 
4 |Walking legs. 
5 |Walking legs. 
LIMULUS AN ARACHNID. 
SCORPIO. 
537 
Sternites. 
Camerostome (of La- 
treille), or upper lip. 
Obliterated by the me- 
siad extension of the 
coxe of the four 
walking legs; the 
two anterior movable, 
the two _ posterior 
fixed. (In Mygalea 
distinctly marked 
small _ prothoracic 
sternite is followed 
by a large oval meso- 
thoracic sternite.) 
—_—_—._ _..____ 
Pentagonal elongate 
sclerite or metatho- 
racic sternite. 
7 \Genital operculum. |Soft integument. 
Tergites. 
Cephalothoracie carapace 
with central and peri- 
pheral eyes. 
A separate narrow band- 
like sclerite. 
8 |Pectine, or pair of|Separate small rect-|A separate narrow band- 
comb-like organs ;| angular sclerite. 
modified gill-book 
projecting. 
like sclerite. 
9 \lst gill-book pair|Aseparate broadtrans-|A separate band-like scle- 
sunkin pulmonary) verse sclerite with] rite. 
sacs. 
stigmata leading to 
pulmonary sacs. 
