GALATHEALINUM BRACHIOSUM 409 



thin and dark-brown, and on the ventral side where they touch one another 

 they are pressed close together. The dorsal ends of the keels are very thin and 

 do not meet. The dermal ridges of the bridle are feebly developed. The dorsal 

 and ventral sides of the mesosoma have broad median tracts of light epider- 

 mis. The hind edge of the mesosoma is clearly delimited and dips forward 

 on the dorsal side. 



The metasoma has a well-developed ventral sulcus (Fig. В 162 A). At the 

 sides it is bordered by rows of very large glandular adhesive papillae occupy- 

 ing the greater part of the ventral surface of the trunk and lying cheek by 

 jowl. Most frequently each papilla bears four or five small cuticular plaques 

 arranged in a more or less straight longitudinal row along its ventral edge. 

 On a few papillae, however, the number of plaques may be as low as three 

 or even two, or as high as ten. Their arrangement is also subject to variation. 

 Each plaque lies on a small oval or round dermal eminence which is light in 

 colour. Twenty-seven metameric papillae can be counted on the right side 

 and 24 on the left. 



The cuticular plaques in this region of the metasoma are scale-like regular 

 ovals with a dark thickened front rim (Fig. D162y4). The very front edge has 

 a narrow clear uniform border and the thick rim just behind it may be seen 

 under high magnification to consist of rows of dense cuticular rodlets. The 

 hind edge of this anterior thickening of the plaque is not clearly delimited. 

 The plaques are 80-90/it across and 50-55/n long. 



The dorsal ciliated band of the metasoma is broad and pronounced, 

 extending to the hind end of the metameric section of the trunk (Fig. 

 В162Я). 



The next part of the metasoma is furnished with large nonmetameric 

 papillae of irregular shape lying on the ventral side of the trunk (Fig. 

 C1625, C). The length of this region is more than four times that of the 

 metameric part. Each papilla bears between two and thirty cuticular plaques 

 arranged in no fixed pattern. The size and shape of the plaques vary con- 

 siderably more than those on the anterior part of the trunk. Oval plaques are 

 most common but one may also encounter round plaques right alongside. 

 The thickened anterior rim of the plaque, moreover, has its sharpest contour 

 not in front but behind and has a coarser microscopic structure (Fig. 

 D1622?, C). The plaques are с 8(V across and up to 6(V long. 



Then follows a comparatively short part of the trunk completely without 

 adhesive papillae. All the rest of the body is missing in our specimen. Near 

 the break, however, there is a single large conical ventral papilla with one 

 cuticular plaque at its tip which differs from those described above. This is 



