89 



from Torres Strait; this question remains, however, undecided, especially because too little is 

 known about the adult male of Haswell's species, of which the petasma has not been described. 



The largest of the four specimens is the male from Stat. 289, that is 69 mm. lon^-. The 

 rostrum, nearly horizontal above, reaches just beyond the i^' joint of the antennular peduncle 

 and is armed with 10 teeth in addition to the epigastric tooth; the foremost tooth, the smallest 

 of all, is situated close to the tip, being just as far distant from it as from the penultimate. 

 The lower margin that rises obliquely upward, is straight, appears even very slightly concave 

 in the middle. The subacute post-rostral carina reaches to the posterior margin of the carapace. 

 Antero-inferior angle of the carapace rather obtuse. 



The abdomen resembles that of the females from the Inland Sea of Japan, the pleura 

 of the first somite show the same incision that runs from their lower margin upward, the carina 

 on the tergum of the second somite is, however, longer and larger than in the Japanese adult 

 females of Trachyp. curvirosiris. 



The antennal flagella are, in the male from Stat. 289, 165 mm. long, a little more than 

 twice as long as the body; the antennal scales just e.xtend beyond the antennular peduncles. 

 According to Spence Bate (I.e. p. 259), the scaphocerite should not extend "quite as far as the 

 e.xtremity of the peduncle of the i^' pair", but in his figure i the peduncle appears distinctly 

 a trifle shorter. In the male from Stat. 289 the antennular peduncle is 11 mm. long, the flagella 

 9,5 mm.; in the largest of the three specimens from Stat. 51, a female long 64 mm., the 

 flagella measure three-fourths the length of the peduncle, in the two other much younger 

 specimens they are but little shorter than it. 



The external maxillipeds reach, in the male from Stat. 289, just to the anterior third 

 of the antennal scales, the legs of the i*' pair extend to the tip of the antennal peduncles^ 

 those of the ^^^ pair reach with their fingers and the slender legs of the 5''' pair with 

 one- third of their propodi beyond the tips of the antennal scales. The legs of the 

 i^' and of the 2"'i pair are unispinose at base, those of the 3"' are unarmed. The thoracic legs 

 closely resemble those of Trachyp. asper Alcock. The legs of the 4''' and of the 5* pair are, 

 however, distinctly more slender and longer than those of the adult females of 

 Trachxp. citrvirostris from the Inland Sea of japan and it is therefore that I conclude that 

 this species is another than that described by Stimpson. In the Japanese species the pereiopods 

 of the 5''> pair reach to the middle, but in the female, long 64 mm., from Stat. 5 i almost to 

 the tip of the antennal scales and in the still larger male from Stat. 289 they extend even 

 with a part of their propodi beyond it. 



The petasma of the male from Stat. 289 closely agrees with the figure i" in the Challenger 

 Report, the two small submedian teeth do not project beyond the lateral lobes, difl'erent therefore 

 from the petasma of Trachyp. curvirosiris, in which they are figured as projecting beyond 

 them (vide: K. Kishinouye, Journal Fisheries Bureau, VIII, N° i, Tokyo, 1900, PI. VII, Fig. 10). 

 The petasma of Trachyp. aspcr Alcock has a quite different form (A. Alcock, Catal. 

 Indian Decap. Crust. Calcutta 1906, PI. IX, Fig. 2'ia). 



The rostrum of the larger female from Stat. 5 i is directed obliquely upward and reaches 

 almost to the far end of the 2"^ joint of the antennular peduncle; it bears 9 teeth, besides 



89 



SIBOGA-EXPEDITIE XXXIX a. '^ 



