396 ZOOLOGY 
Appendages of Scorpio. 
1. Chelicerae. 7. Plates with genital pores. 
2. Pedipalpi. 8. Pectines. 
3. Walking-legs. 9. Lung-books. 
4, 1 10. 5p 
5 “ 11. % 
6. 4 12. % 
The first pair of appendages, or chelicerae, are short, three- 
jointed, and chelate. They are directed forward. The second 
pair, or pedipalpi, are very much enlarged, and six-jointed ; 
they end in a swollen powerful pair of nippers; the coxae or 
basal joints of this pair of limbs have a biting process which 
euards the entrance to the alimentary canal. The remaining 
prosomatic limbs are walking-legs; they are seven-jointed, and 
Fic. 225.—Ventral view of pro- and 
meso-soma of Buthus afer. From 
Leuckart, after Cuvier. 
H 
. Chelicerae. 
. Pedipalpi. 
oe 
© OMA bw 
. Ist to 4th pair of ambulatory legs. 
. Genital operculum. 
. Pectines. 
. 4 pairs of stigmata on the 3rd-6th 
mesosomatic region, 
10. 1st metasomatic segment. 
not chelate. The first and second of these ambulatory ap- 
pendages have their coxal joint enlarged and turned forward, 
and the processes thus formed play some part in the ingestion 
of food. The coxae of the last two pairs of walking-legs are 
fused together, but those of the left side are separated from 
those of the right by a small sternum. 
The seventh pair of appendages, or first mesosomatic pair, 
