632 Transactions. 
* 
fifth peraeopod is small, entirely concealed by the greatly expanded side- 
plate of the fourth segment and consists of a small oval plate representing 
the basis followed by a minute joint which is all that remains of the rest 
of the limb. 
The following amended diagnosis of the genus may therefore be given :— 
Tetradeion Stebbing, 1899. 
^ 
а) 
os 
ж] 
£ 
£5 
B 
zi 
e 
g 
et 
i 
e 
c 
© 
В 
ед 
|) 
Фф 
œ 
эв 
Е 
со 
5 
ge 
= 
F 
i=] 
is i=} 
E 
8 
Ф 
B 
© 
E 
£5 
E 
=) 
parts similar to those of Phippsia. Gnathopoda 1 and 2 similar, not sub- 
chelate, merus and carpus slightly produced, propod amall. Peraeopoda 1 
to 4 slender, basal joints not expanded, 5 greatly reduced, consisting of 
a small plate representing the basal joint. Uropoda short. Telson oval, 
short, entire. 
теры. eae ae 
Fic. 1.—Tetradeion crassum Chilton : 
side view of whole animal. 
The typical species, and at present the only one known, is Tetradeion 
crassum (Chilton) (see references above), the diagnosis of which is included 
in that of the genus. p 
2 Me dark slate, sometimes with lighter patches on some parts of 
e А 
Length of body, in coiled position, about 3 ; greatest breadth, — 
2mm.; depth, 1:5 mm. к {омы = жасай. оша х 
"es: Lyttelton Harbour, Oamaru, and Hawke’s Bay. 
Remarks.—] rom the detailed description given below it will be seen 
that this species presents many similarities in the general shape of the | 
