with Observations on the General Arrangement of the Articulate. 901 



bins there are usually more than thirty-eight, and in one species even so many 

 as sixty joints in the antenna. In Scolopendra there are seldom more than 

 twenty, or fewer than seventeen. But although I have little douht that the 

 number is in reality fixed in each species of the latter genus, it cannot be 

 taken as a good character, as it is often found to vary not only in the antennae 

 of different individuals of the same species, but even in the two antenna? of the 

 same individual. It can only be received as a secondary character, and when 

 the number corresponds in both antennae. 



DESCRIPTION OF TAB. XXXIII. 



Figs. 1 and 2. The ventral surface of one segment of the body of Scolopendra Hopei, Newp. 

 a. The two united sternal plates, b. The episternal. c, c. The epimeral. /. The 

 coxa. ff. The femur, h. The tibia, i. The metatarsus, k, I. The tarsus, m. The 

 claw. 

 Fig. 3. The lateral view of the head of a very young Geophilus, Arthronomalus (Geophilus) 

 longicorniSy Leach, a. The cephalic segment formed of its four subsegments 

 1 to 4. b. The basilar segment, c. The sub-basilar segment, /to in. The great 

 mandible in the progress of development. 

 Fig. 4. Head of Scolopendra Hopei, Newp. a. Cephalic segment, b, c. The united basilar 

 and sub-basilar segments, d. The scutum, e. The episcuta on each side. y. The 

 femoral joint of the great mandibles or foot-jaws. 

 Fig. 5. The under surface of the head of the same species. 5* d. The dental plates, e. The 



subdental plates. 

 Fig. 6. The labrum and palpi : the letters as in fig. 1 . 

 Fig. 7. The maxillary palpi, c, c. The lingua. 

 Fig. 8. The labrum or anterior lip. c, c. The lingua : the other letters analogous to parts 



in fig. 1. 8*. The maxilla. 

 Fig. 9. The inferior surface of the cephalic region of the head, showing the labrum and 



maxilla in situ. 

 Fig. 10. Head of Geophilus subterraneus. a. The cephalic segment, b. The basilar seg- 

 ment, c. The sub-basilar segment. 

 Fig. 11. Head of Gonibregmatus Cumingii, Newp. 

 Fig. 12. Under surface of the same. 



2r2 



