REPORT ON THE SCIllZOPODA. 191 



ITahitat. — Of this form, wliicli may he regnidcMl a representative species of the genus 

 in the soutlicrn hemisphere, several specimens were collected off the Kerguolen Islands, 

 at a depth of 120 fathoms. A single and much larger, though rather mutilated specimen, 

 apparently of the same species, was taken in the Antarctic Ocean from a rather con- 

 siderable depth. The locality is : — 



Station 153, Fol)ruary 14, 1874; lat. G5° 42' S., long. 79' 49' E.; depth, 1675 

 fathoms ; blue mud. 



48. Psexidomma australe, G. 0. Sars (PI. XXXIII. figs. 17, IS). 



Amhlyops nudralit<, G. 0. Sars, Pridiminary Notices on the Challenger Schizopoda, Xo. 4-"). 



Specific Characters. — Ocular plates comparatively smaller than in tlie ])receding 

 species, not occupying the whole breadth of the frontal margin, outer edge smooth, and 

 forming, along with anterior, a projecting corner, from which a longitudinal keel runs 

 across the plate, dividing it into an upper and a lateral area, the latter somewhat hollowed. 

 Autennular peduncle short and robust. Antennal scale twice the length of the 

 antennular peduncle, rather narrow, lanceolate, setose on both edges, spine of outer 

 margin placed close to base of scale. 



Remarks.— Oi this species only a fragment — the most anterior part of the Ijody — was 

 found ill the collection. This fragment shows, however, some very striking peculiarities, 

 fully warranting the establishment of a new species. I formerly referred it to the genus 

 Amhlyops, but now find it, on closer examination, more" properly referable to the 

 genus P.'ieudomma, the structure of the ocular plates being more in accordance with that 

 in the latter genus. 



Description. — The fragment — comprising the anterior part of the carapace, together 

 with the ocular plates, the antennute and antennae — had evidently belonged to a full- 

 grown male specimen. The length of the animal may have probably been about 10 mm. 



The carapace is rather broad anteriorly, with the frontal margin forming an even 

 curve, and the antero-lateral corners almost right-angled. 



The ocular plates (see fig. 17) do not occupy the whole breadth of the frontal margin, 

 and exhibit, moreover, a form somewhat deviating from that in the preceding species. 

 They are, as in that species, truncate anteriorly, and [)artly separated in the middle b}- a 

 short and narrow sinus or cleft, but have the outer edge quite smooth, and forming, 

 along with the anterior edge, a somewhat projecting corner. From the latter a longi- 

 tudinal keel runs across the plate dividing it into an upper part, which is nearly 

 plane, and a lateral one, distinctly hollowed along the middle (see fig. 18). As in 

 the preceding species, no trace whatever of pigment or any visual elements can be 

 detected. 



The antennular peduncle has much the same appearance as in the last species, being 



