=Fam. 3. Homolidae.=—The eyes and antennules are not retractile into orbits. Only the last pair of thoracic limbs are reduced, the sixth pair of pleopods altogether absent. _Homola_ and _Latreillia_, widely distributed, occur in the Mediterranean. _Latreillopsis_ from the Pacific. _L. petterdi_,[151] 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 forward, 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_[152] presents the same peculiarity. [Illustration: FIG. 127.—_Cymonomus granulatus_, × 1. _A.1_, _A.2_, 1st and 2nd antennae; _E_, eye-stalk; _S_, extra-orbital spine of carapace. (After Lankester.) ] _Cymonomus granulatus_ (Fig. 127) is an abyssal form that has been dredged from the Mediterranean and North Atlantic, in which the eye-stalks are curiously tuberculated, and the ommatidia of the eye are entirely unpigmented and degenerate, though a few corneal facets are still recognisable. This species is replaced by _C. quadratus_ in the Caribbean Sea and by _C. normani_ on the East African coast, in which the alteration of the eye-stalks into thorny, beak-like projections becomes progressively marked, and all traces even of the corneal facets disappear. This remarkable genus was mentioned in the excursus on Crustacean eyes on p. 149. [Illustration: FIG. 128.—_Calappa granulata_, from in front, × ½. _C_, Hand of chelipede; _T_, walking legs. (After Garstang.) ]