1448 THE VOYAGE OF H.M.S. CHALLENGER. 



the upper side, the second long, then two short, a long, three short, a long, two short, 

 a long, and a strongly cleft one adjoining the hinge of the fifth joint ; of the cleft tooth 

 the hinder division is the broader and has part of its hind margin finely serrate ; the 

 fifth and sixth joints together are scarcely as long as the fourth, the fifth is slender, the 

 finger not quite half its length. 



Fourth Perseopods. — The decurrent apical tooth of the hind margin in the third joint 

 is not very long ; the front margin of the fourth joint has five teeth, two very small and 

 three larger ; it exceeds the length of the third joint. 



Fifth Perseopods. — The upper part of the first joint considerably wider than the 

 distal end, the remaining joints together shorter than the first, proportions between them 

 as in Primno guerini, except that in the present species the finger is only half the length 

 of the fifth joint ; the pectinate distal border of the finger forms a decided angle with 

 the front margin. 



The First Uropods differ from those of Primno macropa by having the inner margin 

 produced into a small tooth at a little distance from the apex of the plate ; the third pair 

 differ by having the inner as well as the outer margin produced into a tooth, the serrate 

 distal margin being produced into an apex between and beyond them. 



Telson triangular, not broader than long. 



Length. — The length of the specimen was a little over a fifth of an inch. 



Locality.— March 9-10, 1874, south of Australia; lat. 48° 18' S., long. 130° 4' E.; 

 surface ; surface temperature, 5 2° '3. One specimen, female. 



Remarks. — The sj^ecific name is taken from the addition to his name which 

 Guerin assumed, thereby becoming Guerin-Meneville ; an undescribed species was 

 named "Primno Guerinii" by White in 1847. 



Primno antarctica, n. sp. 



Postero-lateral angles of the third pleon-segment not produced. 



Upper Antennae. — The peduncle cylindrical, a single joint longer than broad ; the 

 flagellum a single joint little longer than the peduncle, strongly tapering, carrying three 

 filaments above the centre, and one or two setules near the apex. 



Gnathopods as in Primno latreillei. 



First Perseopods. — Second joint as long as the third; third with a minute sub- 

 apical tooth to the hind margin ; fourth joint longer than the fifth, with a tooth at the 

 middle of the hind margin, and a larger apical tooth, within which there is a spine not 

 quite so long as the tooth ; fifth joint smooth, a little bent at the base ; the finger 

 strongly curved at the tip, more than half the length of the fifth joint, 



Third Perseopods. — First joint channelled behind, expanded a little below the base, 



