134 



Pies. exigua (Rathb.) from the Hawaiian Islands may be distinguished by the rostrum 

 bent strongly downward in front of the eyes, by the abdomen being nearly 4-times as long 

 as the carapace, by the axial diameter of the eyes exceeding the transverse and by its very 

 small size. 



Pies. binoculus (Bate), finally, differs by a larger size, by the frontal crest being higher 

 and more elevated, by the proximal teeth of the upper margin of the rostrum being not 

 separated by a long smooth interspace from the distal teeth and by the much longer and 

 slenderer dactyli of the three posterior legs, that measure one-third of the propocli. 



7. Plesionika binoculus (Bate). PI. XII, Fig. 30. 



Nothocaris binoculus C. Spence Bate, Report Challenger Macrura, iSSS, p. 656, PI. CXIV, fig. 2. 



Stat. 302. Febr. 2. io°27'.qS., I23°28'.7 E. Strait between the islands of Rotti and Timor. 



216 m. Bottom sand and coral sand. 1 male of medium size. 

 Stat. 300. Febr. 8. 8° 27' S., 1 22° 54'. 5 E. Lobetobi Strait between the islands of Flores and 



Solor. 247 m. Bottom sandy mud. 1 male and 3 females, 2 of which are egg-laden. 



The five specimens are in a good condition and, except the male from Stat. 302, all 

 of a larger size than those collected by the "Challenger". 



The largest specimen (Fig. 30) is an egg-laden female from Stat. 306, in which, measured 

 dorsally, the carapace is 20 mm. long, the abdomen, telson included, 54,5 mm. and the rostrum 

 28,5 mm., while the latter proves to be 30,5 mm. long, when measured in a straight line from the 

 orbital margin to the apex: the entire length from apex of rostrum to tip of telson is thus 105 mm. 

 The frontal crest, that rises rather suddenly from the middle of the carapace, is much more 

 elevated and higher than in the figure 2 of Bate's work; this is also the case in the other 

 specimens, even in the young male from Stat. 302, the carapace of which is 11,5 mm. long, 

 so that the figure is certainly inaccurate in this respect. The frontal crest that ascends obliquely 

 from the middle of the carapace, makes in all the specimens an obtuse angle with the 

 rounded posterior half of the latter, but in Bate's figure this is not the case. The rostrum curves 

 at first downward to'the level of 3 rd antennular article and beyond this point gradually rises 

 obliquely upward : in the male from Stat. 306 the rostrum appears as much upturned as in 

 Bate's figure 2, but in the four other specimens it is more strongly upturned. In the two male 

 specimens and in the female without eggs the rostrum is armed dorsally with 13, ventrally 

 with 16 teeth; the first 5 teeth, that gradually increase in size and that are movable, stand 

 on the frontal crest, posterior to the orbital margin ; the following teeth are all fixed, the 6 lh , 

 the largest of all the teeth, stands above the orbital margin and is immediately foliowed by 

 the 7 th which is distinctly smaller, though both the 6 th and the 7 lh are much larger than the 

 following teeth on the upper margin ; in the female without eggs the 8 th tooth, which is but a 

 little smaller than the 7 th , though larger than the following, stands just beibre the eyes, but in 

 the two males the S th tooth is already as small as the following and placed at the level of the 

 boundary between the 2 nd and 3 rd antennular article; the following teeth are subequally distant 

 from each other, except the two foremost teeth that stand close together, the anterior as far 

 from the apex of the rostrum as from the posterior. The largest specimen, the female with 



