144 



terminal joint and two-fifths of the carpus beyond the antennal scale; the carpus (16 mm. in 

 the ova-bearing female) is a little more than twice as long as the terminal joint and slightly 

 shorter than the merus (17,5 mm.): Bate's description, according to which (1. c. p. 647) the 

 merus should be about half the length of the carpus, is therefore wrong. 



The peraeopods of the 2 nd pair are perfectly equal and reach, in the ova-bearing 

 female, by the chela and half the terminal joint of the carpus beyond the antennal scale, in 

 the other female by the chela and the three last joints, in the young specimen by the chela 

 and the five last joints of the carpus. The carpus is composed of 19 or 20 articles-, terminal 

 article 2V s -times as long as the penultimate and 2 1 / 3 -times as long as broad, chela i l / k — i 1 /»- 

 times as long as the last segment of the carpus and nearly just as broad, fingers about as long 

 as the palm. 



In the adult females the legs of the 3 rd pair measure two-thirds the length of the body, 

 rostrum included, and reach by the dactylus, propodus and carpus beyond the antennal scale ; 

 the following legs slightly increase in length, the 5 th leg measuring 8 /n tne length of the body, 

 but, the length of the meri gradually decreasing^ those of the 5" 1 pair reach only along the 

 two proximal fifths of the scaphocerite. The meri of the 3 rd pair are armed with 14 or 15 

 distantly placed spines, those of the 4 th with 11 or 12, those of the 5* pair with 7 or 8 spines. 

 The length of the carpi is nearly the same in the legs, but the propodi distinctly increase in 

 length from the 3 rd to the 5" 1 , so that those of the 5 th pair are about one and a half as long 

 as those of the 3 rd . The dactylus is short and, in proportion to the propodi, the length of the 

 dactyli decreases from the 3 rd to the 5 th leg: those of the 3 rd pair (Fig. 33a?) measure in the 

 full-grown females 1 L or l L of the propodi, in the young specimen a little less than l /. t , those 

 of the 4 th pair in the adult y i0 , in the young specimen a little less than y g , the dactyli, finally, 

 of the 5 th pair (Fig. 33 e) of peraeopods measure in the adult specimens a little less than 1 / 12 or 

 y u , in the young specimen 1 / n of the propodi. The dactyli are nearly straight and slender, so 

 e. g. are those of the 4 th pair of the female with eggs about 7-times as long as broad at base; 

 they taper gradually and are armed near the tip, on their postenor margin, with a short spine 

 that is almost contiguous to the posterior margin and furnished with a few setae at its base, 

 while the margins are for the rest smooth and unarmed. 



I at first did hesitate to refer these specimens to Pies. spinipcs, because in Bate's description 

 "the second pair of pereiopoda is (said to be) unequal, that on the right side being shorter and 

 more slender" (C. Spence Bate, l.c. p. 647). As a rule, however, in those species in which the 

 legs of the 2 nd pair are unequal, the shorter leg appears also less slender than the other: the 

 right leg, figured in Fig. 2 on Plate CXIII, presents, however, a rather not slender form. In 

 this figure the i st tooth of the upper margin of the rostrum stands much more backward than 

 in the specimens from Stat. 251 and the rostral teeth are in these specimens not so far distant 

 from one another as in the subjoined figure. I therefore applied to Dr. Calman of the British 

 Museum, who with his usual obligingness wrote me the following : 



"Of Plesionika spinipes all the type-specimens are now more or less broken. The only 

 one that has both rostrum and telson complete has the following dimensions: 



