vI BRACHYURA—OXYSTOMATA 185 
and Latreillia, widely distributed, occur in the Mediterranean. 
Latreillopsis from the Pacific. ZL. petterdi,’ a magnificent species, 
with the carapace nearly a foot long, and with very long legs 
like a Spider-crab, has been dredged from 800 fathoms east of 
Sydney, New South Wales. 
Tribe 2. Oxystomata. | 
This group comprises Crabs whose carapace is more or less 
circular, while the mouth, instead of being square as in the 
remaining Brachyura, is triangular with the apex pointing for- 
ward, and the third maxillipedes are not expanded into the 
flattened, lid-like structures found in other Crabs. There is the 
same tendency in some of the genera for the posterior thoracic 
limbs to be reduced and carried dorsally, as in the Galatheidae 
and Dromiacea. The well-known Dorippe from the Mediterranean 
has this feature, and frequently carries an empty shell upon its 
back, and Cymonomus” presents the same peculiarity. 
Gymonomus granulatus (Fig. 127) is an abyssal form that has 
Fic, 127.—Cymonomus granulatus, x 1. A.1, A.2, Ist and 2nd antennae ; #, eye- 
stalk ; S, extra-orbital spine of carapace. (After Lankester. ) 
been dredged from the Mediterranean and North Atlantic, in which 
the eye-stalks are curiously tuberculated, and the ommatidia of 
1 M‘Culloch, Rec. Australian Mus. vi. part 5, 1907, p. 353. 
2 Lankester, Quart. J. Mier. Sci. xlvii., 1908, p. 439. 
