Myriopoda of the ^Challenger ' Expedition. 137 



squaniiform tubercles that are so cliaracteristic of the succeed- 

 ing segments becoming gradually more and more manifested. 

 The rest of the segments with their posterior portions loii- 

 gitudinallj grooved or wrinkled from base to summit and 

 furnished with 8 equidistant, spiniform, squamiforin tuber- 

 cles_, forming 8 longitudinal rows of spines : the lowest of 

 these series is situated just below the middle of the side 

 and begin on the seventh segment ; the second series, 

 beginning at the sixth segment, is situated just below the 

 level of the pores, the spines are larger than those of the 

 lowest series ; the upper series on each side is composed 

 of flatter tubercles, which, nearly obsolete on the anterior 

 segments, become spiniform only at the hinder end of the 

 body; in the middle line of the dorsum there is a faint indi- 

 cation of a similar series of tubercles. The tubercular area 

 of the segments is lightly elevated and separated from the 

 anterior area, which is rugose and finely transversely striolate 

 in front, by a shallow depression representing the transverse 

 sulcus. Pores conspicuous, situated in front of the sulcus 

 and just above and in front of the large tubercle of the median 

 lateral series ; the anterior pore far below (1'5 millim.) the 

 level of the rest, and situated immediately in front of the 

 tubercle, which is itself lower than those on the rest of the 

 segments. Sterna finely striolate transversely. 



Anal somite large ; tergite without spines but rugulose, the 

 posterior angle elongate but not surpassing the summit of the 

 valves ; valves with strongly compressed margins, finely 

 rugulose in front, coarsely rugose and punctured behind ; 

 sternite large and angular. 



Legs longish and slender, with a single seta below each 

 segment, except the tarsus, which has about three ; the ante- 

 rior legs, at least in female, shorter, thicker, and more setose 

 beneath. 



Number of segments 50. 



Length 111 millim., width 11. 



Loc. Wokan Dobbo (Aru Islands). 



Acanthiulus Blatnvillei, Le Guillou'^, from New Guinea, the 

 only other known species of the genus, differs from this new 

 form, if we may trust Gervais's figure, in having the antennfe 

 shorter than the face, the antero-lateral border of the coilum 

 less widely emarginate, and the posterior angle more strongly 

 produced. Moreover the spiniform tubercles are well deve- 

 loped on the anterior segments. 



* Bull. Soc. Phil. Paris, 1841, p. 86 ; Gervais, lus. Apt. iv. p. 173, 

 pi. xliv. fig. 8. 



Ann. & Mag. N. Hist. Ser. 6. Vol. xi. 10 



