270 



however, not overlook the fact that the dactykis of the external maxillipeds is differently 

 inserted to the propodus : in Thaiunastoplax it is implanted at the antero-external angle of 

 the propodus, and the internal angle is bulging outward, whereas in Tetrias exactly the reverse 

 is shown. In TJiajcmastoplax (at least in T. oriental is and T. chuenensis) there is also a 

 transverse row of hairs across the maxillipeds. The abdomen of the cf , however, differs widely 



in both genera. 



Similar feathered hairs as are repeatedly spoken of in describing the external maxillipeds 

 completely cover the chelipeds and to a lesser extent also the walking legs. Beneath this soft 

 coatino- numerous pearly granules are hidden on the chelipeds ; these granules assume the 

 shape of projecting, obtuse spines along the basal half of the outer border of the meropodite, 

 the anterior margin of the carpopodite, and the inferior border of the chela, where they are 

 continued to the tip of the immovable finger. The chelae are equal in size, much compressed, 

 as hio-h as long, and slightly longer than the fingers; the outer surface is provided with longi- 

 tudinal rows of granules, the inner surface is devoid of granules, but in the middle a longitudinal 

 row of hairs is found; the fingers are short, high at the base, not greatly curved near the tip, 

 compressed, slightly gaping, back of dactylus with long hairs, cutting margins of both fingers 

 nearly entire. 



The walking legs are rather short, the first three pairs subequal (the second pair slightly 

 the longest) and about lY^ times the length of the carapace, the fourth pair is greatly reduced 

 in size and reaches only to the end of the meropodite of the preceding pair. The lower surface 

 of the legs is almost naked, but the upper one thickly clad with soft hairs, very long along 

 the margins. Meropodite not yet three times as long as broad, not widening distally, lower 

 border finely crenulate; carpo- and propodite short, with a longitudinal row of very 

 long, feathered hairs on dorsal surface, all directed inward. As these hairs 

 are continued on the upper side of the dactylus and the likewise long hairs 

 along the inner border of the propodite also fringe the inner side of the 

 dactylus, the latter, which is very short, is almost completely hidden. The 

 lower border of the meropodite of the last pair of legs (fig. \b) bears some few spines, 

 and the hairs of these legs are by far not so densely crowded as is the case in the preceding 

 pairs. At the inner border of the propodite, near the base of the dactylus, two spines are 

 placed side by side. 



The long and narrow abdomen of the cf, with the terminal segment nearly circular 

 and reaching quite to the external maxillipeds (as the deep trench of the sternum receiving 

 the abdomen is continued forward into the buccal cavity), has been well described by de Man. 

 The first abdominal appendages are flattened, hairy and reach beyond the middle of the fifth 

 segment of the abdomen; their distal part is curved somewhat outward and the tip is obtuse. 



Ihe type species, T. scabripes Rathbun, is distinguished by the more distinctly-rectan- 

 gular, not transversely-oval, carapace, with a spinule on outer part of hepatic regions, and by 

 the basal parts of the meropodites of the first two pairs of walking legs being armed with 

 I — 3 spinules. 



The present species has been found at New Caledonia, Amboyna and the Andamans. 



