REPORT ON THE SCHIZOPODA. 189 



of the eyes and the extremely slender filiform legs, three northern species have been 

 recorded, viz., Pseudomma rosexim, G. 0. Sars, Pseudomma affine, G. 0. Sars, and 

 Pseudomma truncatiim, Smith. Two additional species, to be described below, were 

 met with on the Challenger Expedition, both in the southern hemisphere. They are 

 readily distinguished from each other by the form of the ocular plates and the antennal 

 scale, as follows : — 



Ocular plates with upper face plane and outer edge serrate. Antennal scale oblong, 

 with inner corner only slightly projecting; spine of outer corner far removed from 

 base, . . . . . . . . .P. sarsii, Suhm. 



Ocular plates divided by a longitudinal ridge, outer edge smooth. Antennal scale 

 lanceolate, with inner corner greatly projecting ; spine of outer corner placed close 

 to base, . . . . . . . . .P. anstndc, G. 0. Sars. 



47. Pseudomma sarsii, Willemoes-Suhm, MS. (PI. XXXIV. figs. 1-3). 



Pseudomma sarsii, G. O. Sars, Preliminary Notices on the Challenger Schizopoda, No. 46. 



Specific Characters. — Form of body very slender. Carapace evenly emarginate 

 behind, leaving the two posterior segments of trunk uncovered above. Last caudal 

 segment longer than preceding. Ocular plates occupying almost the whole breadth of 

 frontal margin, obtusely truncate anteriorly, outer edge partly serrate, upper face plane. 

 Antennal scale oblong, with denticle of outer corner not far distant from apex, inner 

 corner but slightly projecting and bluntly rounded. Telson about as long as last 

 segment, linguiform, apex broadly rounded and armed with ten strong spines, the six 

 innermost rather long ; lateral denticles very small. Uropoda of usual structure. 

 Length, 14 mm. 



Remarks. — This form was recorded by the late Dr. v. Willemoes-Suhm in his 

 manuscript notes, under the above given name, and a figure added of the animal as 

 viewed from above. It is closely allied to the typical species, Pseudomma roseum, G. 0. 

 Sars, or perhaps still more to the Arctic form, Pseudomma truncatum. Smith, but may 

 readily be distinguished from both by a somewhat deviating form of the antennal scale 

 and by the armature of the telson. 



Description. — The usual length of this form would seem to be about 14 mm., or 

 somewhat less than that of Pseudomma roseum. There is, however, in the collection a 

 single very mutilated specimen from the Antarctic Ocean, which is rather larger in 

 size. 



The form of the body (see PL XXXIV. fig. l) is very slender, and rather similar to 

 that of Pseudomma roseum, being nearly cylindrical throughout, with the anterior 

 division but slightly dilated. 



The carapace is comparatively small and narrow, not nearly covering the whole 



