296 Mr. Newport on the Class Myriapoda, Order Chilopoda, 



them ; but approximated together at their inner anterior margin, which, united 

 with the epimeral plates (c), forms the denticulated front of the labium. The 

 space between the plates is gradually filled up in the young animal, partly by 

 a widening of the plates themselves, and partly by the consolidation with 

 them in the middle line of the remnant of the atrophied sternal plate of the 

 preceding segment, that has given origin to the posterior pair of palpi (fig. 6.). 

 The deep sulcus in the middle of the labium of the perfect animal is the indi- 

 cation of these unions. In Cermatia the close approximation of the episternal 

 plates in the middle line does not take place, but the two remain distinct 

 throughout life ; while the epimeral plates, that form the border of the lip, 

 have their denticulations elongated into spines. These epimeral plates are 

 well developed in Scolopendra (fig. 5*), and are indicated by sutures, although 

 they are absent in Geophilus ; are developed without marginal teeth in Gyp- 

 fops ; and are small, and consolidated with the episternal plates in Lithobius 

 (fig. 31, d) and Cermatia. In Scolopendra they are often formed each of two 

 pieces, analogous to those on the segments. I have distinguished these as the 

 dental and subdental plates (d, e). The latter are very minute and without 

 denticulations, but are marked by sutures, which distinguish them from the 

 episternal pieces, as other transverse sutures divide the latter from the sternal 

 (fig. 5.). 



The chief parts which we have traced in the mandibles and inferior surface 

 of the basilar segment, exist also in the other organs of nutrition and their 

 segments. Thus, in the part which has been described by Savigny and others 

 as the Jirst auxiliary Up (fig. 6, b,f), which is situated anterior to the struc- 

 tures we have just examined, and is the sternal portion of the fifth segment of 

 the head,— the true sternum is atrophied, and united in the middle line with 

 the episternal plates of the succeeding segment, the great basilar region, as we 

 have seen in Lithobius. But the episternal plates remain as broad irregular 

 laminae (fig. 6, b), articulating on their front with two transversely elongated 

 plates, the analogues of the coxse (/), which form the margin of this auxiliary 

 hp. Both these plates articulate conjointly at their sides with the third joint 

 of the palpus, which may be regarded as the analogue of the labial palpus of 

 Insects. This third joint represents the femur, and the two remaining joints 

 the tibia and tarsus, with the minute claw. Precisely the same structure exists 



