286 "TERRA NOVA" EXPEDITION. 



in P. armata it is actually at the apex, (4) the uropods are more unequal in length. 

 Dana does not mention or figure the prominent spine on the inner uropod, which is 

 so characteristic a feature of Hansen's species. These differences are small, and may 

 well disappear in the light of an examination of Dana's type, if it is available. 

 Hansen's species was obtained in the waters of the East India Archipelago, and 

 Zimmer (1915 (2)) and Colosi (1918 and 1920) have also recorded it from the same 

 area. The geographical distribution of the two species is therefore not inconsistent 

 with their specific identity. 



10. Promysis atlantica, sp. nov. (PI. I, figs. 5-6.) 



Occurrence. — Off Rio de Janeiro, Station 39, one female, immature, 4 mm. 

 DescrijJtion. — Agreeing closely with the description and figures of P. armata 

 (Hansen), differing only in the following points : — 



1. The eyes are longer in proportion to their breadth (2|- : 1), and the cornea is 



only half as long as the stalk. In P. armata, female, the eye is one and 

 a half times as long as broad, and the cornea is only slightly shorter than 

 the stalk. 



2. The rostral plate is shorter and more broadly rounded. 



3. The antennal scale extends only to the middle of the third joint of the 



antennular pedimcle. In P. armata it is slightly longer than the 

 anteimular peduncle. 



4. The cleft of the telson is equal to one seventh of the total length of the telson. 



In P. armata it is one quarter. 



5. There are eighteen spines on the lateral margin of the telson, confined to the 



distal three-fifths of the margin. In P. armata there are twelve spines 

 occupying the distal five-sixths of the margin. In P. atlantica, 

 therefore, there is a proportionally longer part of the margms of the 

 telson unarmed, and the spines are more numerous and more crowded. 



6. The endopod of the uropods is at least as long as, even slightly longer than 



the exopod. It bears sixteen spines on its inner margin, the two distal 

 ones longer than the rest, slightly curved and situated at the apex. 

 In P. armata the endopod of the uropods is slightly shorter than the 

 exopod, though the arrangement of the spines is closely similar to that 

 in P. atlantica. 



P. atlantica bears a prominent spiniform protuberance on the outer face of the 

 inner uropod similar to that in P. armata, but perhaps blunter. 



The discovery of an Atlantic species of this genus is noteworthy. While it appears 

 to be distinct from the Indo-Pacific species, there can be no question that it belongs 

 to the same genus, which, therefore, presents an interesting case of discontinuous 

 distribution. The genus is presumably pelagic and this may explain its wide 



