I. '08. 96 



The first pair of pereiopods, which only possesses rudiments 

 of the microscopic chelae found in Paudaliis, is about the same 

 length as the outer maxillipcdes. The second pair reaches 

 slightly beyond the carpus of the first, and is symmetrical. 

 Distally the carpus shows eight to ten very distinct annula- 

 tions, while twelve or fourteen more, which are nnich less 

 clearly defined, may be seen in the proximal part. The last 

 three pairs of pereiopods are very long and slender; the fifth, 

 which is the longest of all, is in a female specimen more than 

 two and a quarter times the length of the first pair ; in fact, 

 the propodus alone is considerably longer than that limb. The 

 dactyli of these last three pairs are shoi't and the merus of each 

 is armed ventrally with a number of short spines the precise 

 number of which seems subject to much variation. The exact 

 length of these limbs is by no means constant ; the female 

 specimen mentioned above probably represents an extreme 

 case. 



The branchial jormula is the same as in Pandalus Montagui. 



In the male the endopod of the first pair of pleopods (fig. 3j 

 is internally concave, with a broadly rounded apex. It is 

 thickly setose on the proximal half of its convex outer margin ; 

 internally it is provided with a fringe of much shorter setae 

 at its middle and with a series of minute hooks nearer the apex. 

 In the female the endopod (fig. 4) is strongly setose on both 

 margins and is produced to a narrow and acute termination. 

 The eggs are very small and extremely numerous. The outer 

 uropod is much longer than the inner and is about four times 

 as long as wide. 



Colour in life. — The carapace and abdomen are thickly 

 sprinkled with bright red chromatophores ; the former is dor- 

 sally of a dark purple tint, while in the latter the red pigmen- 

 tation is darker on the x^osterior portions of each somite. The 

 rostrum is bright red distally, less deeply coloured proximally. 

 The eyes are black, with golden reflections ; the antennules are 

 red, and the antenna and antennal scale are more sparsely 

 pigmented with the same colour. The outer maxillipedes and 

 pereiopods are more or less thickly spotted with red ; the pleo- 

 pods, telson and uropods are light red. All the fringes of 

 setae are golden in colour. 



Size.— The largest specimen examined measures 110 mm. 

 from the back of the orbit to the apex of the telson. In this 

 example the rostrum is broken. In the largest perfect ex- 

 ample the above measurement is 108 mm., or from the tip of 

 the rostrum to the apex of the telson 169 mm. 



Alcock (1901) suggests that Plesionika sernilaevis, Spence 

 Bate, should be regarded as a synonym of P. martia. With 

 this view I am inclined to agree, although the rostra of the 

 Challenger specimens are considerably shorter, in proportion, 

 than those of the Irish examples. 



