680 CHILOGNATHA. 



1863. Plate vi, fig. 58-61) arc arranged much as in S. margi- 

 natus. It differs remarkably, however, in the raised posterior 

 margin of the segments, giving a serrate outline to the body. 

 In this respect it seems to combine the characters of the pres- 

 ent family and that of Spirostrephon, a genus in many 

 respects intermediate between the Polydesmidce and the 

 Siphonantia. Four spiracles are represented on the tenth to 

 the thirteenth segments from the head. 



The genus Spirostrephon is in many respects intermediate 

 between this and the succeeding family, the sterna being soft, 

 as in the Siphonantia. S. Copei Pack, was found by Mr. C. 

 Cooke in Mammoth Cave. 



SIPHONANTIA Brandt. In the sucking Myriopods (Sugantia 

 of Brandt) we meet with the lowest, most worm-like forms of 

 the sub-class. The head is very small and concealed beneath 

 the prothoracic ring. The parts of the mouth are fused and 

 united into a sucking tube for the imbibition of fluids. The 

 eyes are either present or absent, and the scuta, or tergites, 

 may be prolonged laterally into laminae which afford protec- 

 tion only to the back and flanks, the central part of the abdo- 

 men being soft. The feet are small and hidden beneath the 

 broad body, while the male appendages are placed on the 

 seventh segment. In Octoglena the eight eyes are arranged 

 in two converging rows. 0. bivirgata Wood is brown, with a 

 reddish stripe on each side, with about forty-five segments to 

 the body. In Brachycybe the rostrum is acute, much shorter 

 than the antennae, while the body is broad and flattened. 

 Urachycybe Lecontei Wood inhabits Georgia, and has long 

 lateral expansions to the tergites. 



PERIPATIDEA. 



This group is perhaps equivalent and allied to the Myrio- 

 poda, with some affinities to the Tardigrades. Peripatus has 

 numerous pores or stigmata, from which fine trachea} arise. 

 The body and appendages are not jointed, the thirty pairs of 

 legs ending each in two claws. P. Edwardsii inhabits 

 Venezuela. 



