CRUSTACEA. 
67 
Genus, Pirimela. 
... ^Ti front and aljont as wide as long, 
“ Carapace rounded in iron , articulation 
strongly embossed, and toothed at *1"® ^^s in- 
of the inner foot-jaws giving insertion to the next on 
fte g»". “ 1“"^ ”“*rfLre°S“ 
foot- jaws are advanced over the epis 
r J, %r„1nn Brit pi. 3; Milm 
PiRIMELA DENTIOULATA. — ^ ^ ^ . 
Edwards, EM. des Crustacea, t\, p. 4i • 
“This is the only known species of the Genu , 
“SZ'Ln t.le. all »u.d »ast .jd « «r 
two placo. m Mood. » “ » “P“”’ ' 
is generaUy taken in the trawl refuse. 
PORTUNIBM—^^-^^^ Crabs.) 
Genus, Caroinus. 
Terminal articulations of the hindmost legs 
flat and broad, carapace broader than long, front _ 
Carcinus MdENAS-Common Harbour Orab^W Malawi 5 
Pennant, pi. 2, fig. 5; MUne Edwards, Eist. des Crust,, oL , 
of/o/the commonest crabs of our 
under stones on the beach but never goes ^ 
is a hardy species, easily kept in 
obserration, and has even survived ^ 
water It lives in fresh water streams where the sea enters. 
deUtomcot of thi. col ho. be." «b.ervod throogh 
oil it. ,togo. from the .»« to «■» “!f 1“”' 
one of progressive morphology.— (Vide Phil. Trans.) 
Genus Portumnus. — Leach, Bell. 
“ ’ Platyonychus.— Etst. des Crust., 
V.l, p. 434; Couch. 
“ Hinder legs with a wide and oval joint ; corresponding part 
of the other legs straight and unfit for swinging 
This definition of Couch’s is scarcely ^ 
tho Genus from that of PorUmus. Portumnus is easily detected by 
