TANAIDACEA AND MARINE ISOPODA FROM JUAN FERNANDEZ 549 
what rounded. 2nd joint somewhat shorter than the Ist, distally narrowed to 
a broadly rounded process reaching to about ¥/, of the length of the 3rd joint, 
which is a little shorter than the 1st. The flagellum consists of 11 joints. 
Antennae. The first 3 joints small, subequal, together slightly longer than 
the 4th, which is broader but about as long as (very slightly shorter than) 
the 5th. Flagellum on both antennae somewhat incomplete; probably it is 
normally about of the same length as the peduncle. Of the flagella there 
remain I2 and 13 joints respectively. 
Mandibles, 1st and 2nd maxillae, maxillipeds Figs. 11 b, c, d, e. 
Ist peretopods (fig. 11 f). Merus considerably thick with 3 spines on the 
lower margin, one at the middle of the joint and 2 spines near the distal end. 
Propodal joint with its lower distal corner produced into a scale-like projec- 
tion with setae on its rounded margin. 
2nd peretopod (fig. 11 g). Merus thick with 6 spines on the lower margin, 
4 at the middle of the joint and 2 at the lower distal angle. Propodus with its 
lower distal corner scale-like and setiferous. 
3rd peretopod. Ischium on its lower margin with 2 short distal spines. 
Merus thick with 5 spines, 4 at the middle of the joint and 2 at the lower 
distal angle. Propodus with its lower distal corner scale-like and setiferous. 
The 4 posterior peretopods with a great number of short spines. Fig. 11 h 
shows the 4th pereiopod. 
2nd pleopod. The male stylet reaches to about ?/, of the lengths of the 
endopod. 
Uropods. Both rami reach about as far as to the end of the abdomen. 
Inner ramus slightly broader than the outer, triangulate, with the distal margin 
truncate. Outer ramus ovate-lanceolate, with distal end rounded. The setae 
on the margins have mostly been lost. . 
Remarks. 
This species is closely allied to, perhaps the same species as Aega 
urotoma Barnard from the Cape of Good Hope, but the eyes are still closer 
to each other, the distance between them being only 7/,—?/, of their greatest 
diameter. The merus of the first pereiopod has, besides, a smaller number of 
spines than in the last species. 
Fam. Sphaeromidae. 
Group Hemibranchiatae Hansen 1906. 
Genus Exosphaeroma Stebbing 1900. 
Exosphaeroma calcarea (Dana 1854), Stebbing 1914; Sphaeroma calcarea 
Dana 1854, Dollfus 1891; Exosphaeroma Coatsii Tattersall 1913. 
7 immature specimens, 2 males 5 females, longest specimen about 6 mm. 
Loc. Juan Fernandez, Masatierra, 30—40 m, sand with calcareous algae. 
Distribution: Tierra del Fuegia, Falkland Islands, St. Paul (TATTER- 
SALL 1913). 
