6 Proceedings of the Royal Irish Acaderit/J. 



unusually broad in proportion to their length. They show, in the main, the 

 arrangement of part-s characieristic of the !Machilidae. In the maxilla, the 

 galea (figs. 6^, 9, 10) is remarkably broad and flattened, its free border 

 merging into a delicate membranous ridge, strengthened by rib-like 

 thickenings, and its outer corner bearing a group of minute sensory spines 

 projecting from papillae (figs. 10, 11). The lacinia (figs. 6Z, 7, 8, 9) exhibits 

 in perfection the large and wonderfullj' formed head to which reference has 

 been made in the generic description. From the terminal teeth (t) a 

 lamella {la) extends on either aspect, embracing a considerable cavity from 

 whose recesses spring more than fifty lanceolate bristles forming the 

 characteristic "brush." Such a brush, though in a far less highly developed 

 condition, has been figured by Boruer ('08, PL VI. fig. II) from a Japanese 

 species of Machilis, and by the present writer ('13, PI. II, fig. 6 a) in 

 Petrobius. Borner calls the structure " der Mittelanhang." The hinder edge 

 of the lamella (see figs. 7, 8 la) is produced into three prominent teeth t') ; its 

 front edge (fig. 9/«) has a rather sinuate margin, but ends in a single, sharp, 

 delicat« tooth (<"). The maxillary palp (fig. 6^) is of the usual form, its first 

 segment with a strong backwardly directed conical process, its succeeding six 

 segments with the proportionate lengths 10 : 10 : 8 : 11 : 9 : 13. The whole 

 palp measures 5 mm. in length ; the terminal segment as usual bears many 

 strong spines. The labium (fig. 12) has a relatively broad and short 

 sub-mentum ; the terminal segment of the labial palp carries a number of 

 rows of tiatteued tapering sensory spines 'fig. 13). 



'I'he short claws and the dense scopulae below the terminal segment of 

 each foot (fig. 17) give the insect a very characteristic appearance. The 

 bristles of this scopula have a regular lanceolate shape towards the tip 

 (fig. 18;, but this specialized condition can be traced through a series of 

 gradations from the ordinarj' bristles of the leg. The coxal process of the 

 second leg (fig. 15) is narrower than that of the hind-leg (fig. 16). 



Of the a.bdomiiud segincnts, the first (fig. 19) is remarkable for the 

 reduced sternum, the second for the hairy, unspiued stylets (tig. 20), and 

 most of the others for the sinuate sutures between the sub-coxae and the 

 sterna. The male genital segments (figs. 24 and 25; do not call for special 

 remark ; the ^jc7jis (/>) and 'juiw.pojjhyses are short : the latter show imperfect 

 jointing, and bear numerous spines in rows along their inner faces (fig. 26). 

 The stylets of the eighth and ninth segments have very long spines. In the 

 female the gonapophyses are relatively short, with sixty-four rings on those 

 of the eighth, and au equal number on those of the ninth, segment. 



