286 



T. FUKUDA : 



length, the width of the anterior as well as the posterior margins being 

 about g the length. The antero-lateral angles are slightly produced, 

 while the postero-lateral are obtuse and rounded. Gastric sutures run 

 a little divergent posteriorly. Exposed thoracic segments increase in 

 length gradually backward, of which the fifth segment is completely 

 exposed dorsally, the next two having laterally produced and truncated 

 margins. The lateral margins of all the abdominal segments are 

 provided with carinae, which do not end in spines. There are some 

 three or four pairs of longitudinally-marked depressions on the fifth 

 segment ; while the sixth is completely covered with irregularly-marked 

 depressions, and bears tour prominences besides the carinae near the 

 margins. 



The telson is nearly as long as wide, being about -\ the total 

 length ; it is provided with three conspicuous prominences arranged in 

 the same way as in, e.g., P. cercbralis, the median one being triangular 

 and the lateral nearly elliptical. The whole dorsal surface of the telson, 

 except the summits of the prominences, is covered with irregularly- 

 marked depressions as in the sixth abdominal segment. The posterior 

 margin is divided on each side into three lobes, all nearly equal in 

 size, and each with a carina upon the surface. A narrow median 

 fissure, beginning on the posterior margin, reaches almost the middle 

 of the telson ; the space adjoining it being markedly lower and more 

 depressed than the rest. The inner margins of the submedian lobes 

 are beset each with a row of eight spinules, of which the outermost 

 one is mobile and much larger than the rest. The intermediate and 

 the lateral lobes are also provided each with a spintile on the inner 

 margin. All these lobes and spinules point obliquely upward. The 

 lateral margins of the telson have a longitudinal carina, upon which 

 some depressions are present. 



The surface of the basal segment of the uropoda bears also some 

 irregularly-marked depressions : of two prolongations, the outer one is 

 much longer and broader than the inner one. The proximal segment 



