Pies. exigua (Rathb.). It is a species of a rather smal! si/.e, the largest specimen, an ova- 

 bearing female, being 52 or 53 mm. long from apex of rostrum to tip of telson ; the carapace 

 of this female is 9,2 mm. long, the rostrum, measured in a straight line from the orbital margin 

 to the apex, 14,6 mm. and the abdomen nearly 29 mm. In its outer appearance this species 

 ibig. 29) much resembles Pies. binoculus (Bate), the rostrum being as strongly upturned and the 

 abdomen being bent at a right angle at the third abdominal segment. In the adult full-grown 

 species the rostrum is about one and two-thirds to one and three-fourths as long as the carapace, 

 when the rostrum is measured in a straight line from the orbital margin to the apex; in the 

 younger individuals it is almost twice as long as the carapace, in the youngest male the 

 carapace measures 5 mm., the rostrum 9,5 mm. and in the young specimen these numbers are 

 respectively 4 mm. and 7,6 mm. The dorsal crest (Fig. 29a:) begins about at the anterior third of 

 the carapace, but, while in Pies. binoculus this crest is high and elevated, in Pies. assimilis it 

 is very low and while, according to Miss Rathbun's description, the rostrum of Pies. exigua 

 is curved strongly downward in front of the eyes, in this nevv species the frontal crest is very 

 little deflexed and runs almost horizontally forward as far as the distal extremity of the 2 nd 

 antennular article; from here it is strongly curved upward. The rostrum is slender, not widened 

 at base and tapers regularly to the tip. Like in Pies. rostricrescentis and Pies. binoculus the 

 fust hve teeth of the dorsal crest are movable, except only in one ova-bearing female, in 

 which there are four and in this female the 4 movable teeth stand all on the carapace. In the 

 other specimens the 5 th tooth stands above the orbital margin or just before it. The movable 

 teeth gradually increase in length and are foliowed by 2 or 3 fixed teeth ; the 6 th tooth is a 

 little larger than the 5 th , the 7 111 as large as the 6 lh , the 8 th a little smaller; these 2 or 3 fixed 

 teeth stand between the orbital margin and the distal extremity of the antennular peduncle, at 

 unequal distances. In front of the tip of the antennular peduncle a more or less long part of 

 the upper border is smooth and unarmed, nearly as in Pies. rostricrescentis, while 3 or 4, 

 rarely 2, teeth, also fixed, stand near the tip at unequal distances; so e. g. in the youngest 

 male of the 4 distal teeth two stand close to the tip, the anterior as far from the penultimate 

 as from the apex of the rostrum, the penultimate as far from the apex of the rostrum as from 

 the 3 rd or antepenultimate tooth, while the 4 th is twice as far distant from the antepenultimate 

 as the latter from the tip of the rostrum; in the largest specimen, an eggdaden female, there 

 are also 4 distal teeth, but the posterior or 4 th is as far distant from the 3 rd as the 3" 1 from 

 the extremity of the rostrum. The lovver margin is usually armed with 11, more rarely with 

 10 or 12 teeth; the i st stands near the far end of basal antennular article, while 3 or 4 distal 

 teeth stand often at somewhat larger distances than the preceding and the foremost tooth is 

 placed a little distant from the tip of the rostrum. 



Antennal spine stnall, reaching to the anterior margin of the 2 nd joint of the antennal 

 peduncle, branchiostegal spine much smaller, minute. Abdomen, telson included, about 3-times 

 as long as the carapace and one-fourth longer than carapace and rostrum combined. Third 

 abdominal tergum slightly compressed, its posterior margin a little convex. Sixth abdominal 

 somite in the adult female nearly once and a half as long (4,4 mm.) as 5 th (2,7 mm.). Telson 

 (6,3 mm.) almost as long as the 5 th and the 6 th somite taken together and one and a half as long 



