ANATOMY OV SPH^EOTHERIFM. 163 



are brouglit into close apposition, and the spaces that are left 

 along the inrolled margins of the ventral line are completely 

 covered by these processes of the first tergite, rendering the animal 

 quite safe from attack. 



The ventral surface is protected by two rows of chitinous plates 

 on each side. These are figured and shortly described by Brandt 

 {loc. cit.). Corresponding to each of the tergites, except the first, 

 is a ventro-lateral plate roughly quadrilateral in form, with the 

 angles rounded ofE. There are thus eleven of these plates on 

 each side of the body ; and they are set nearly at right angles to 

 the pleura of the tergites, which project some way beyond them 

 ventrally. Interiorly to the ventro-lateral plates is a row of 

 twenty-one smaller chitinous plates, on each of which is a tra- 

 cheal opening. They may be called the tracheal plates. Of 

 these, the first three belong to the first three segments of the 

 body. The remaining nine segments have a pair of tracheal 

 plates on each side. 



There are twenty-four pairs of appendages in the female and 

 twenty-seven pairs in the male SphcerotJierium. The antennas 

 ave sunk in deep fossae on the sides of the head, at once distin- 

 guishing this genus from Glomeris. They are sis-jointed ; the 

 termiual joint is truncated and bears a terminal sense-organ, 

 which I shall describe in detail further on. Brandt speaks of 

 seven joints ; from his figures it appears that he has counted the 

 plate on which the sense-organ is placed as a seventh joint. 



The mandibles are two-jointed, and are typically those of a 

 Diplopod. As in all other Diplopoda, the maxillae are fused 

 together to form a broad plate behind the mandibles. 



There are twenty-one pairs of walking-legs in both the male and 

 female Splicerotheriuvn. The first three segments behind the head 

 bear one pair of legs each. The remaining nine segments each 

 bear two pairs of legs. The legs are six-jointed, the terminal joint 

 bearing a small claw. They are well figured by Brandt. The 

 genital openings of both the male and female are on the basal 

 joint of the second pair of legs. An account of these openicgs 

 and the chitinous valves surrounding them is given by Karsch 

 (loc. cit.), who considers them to be of systematic value. JSTo 

 external organs of copulation are connected with the male 

 openings. 



In the female the twenty-first pair of legs is succeeded by the 

 anus, which is guarded by a pair of lateral chitinous valves. 



14* 



