NUDIBRANCHIATA. 563 



very irregulai- .shape. Those on the median patches are arranged in three not very distinct 

 lines. 



Gen. Fryeria Gray. 



The shape of the animal and arrangement of the tubercles much as in Phyllidia but 

 the vent is terminal, beneath the mantle edge, interrujiting the branchial circuit. 



26. Fryeria Ruppellii Bergh. 



One specimen from the W. side of Ftxdifolu Atoll, Maldives, 70 /., 1-5 cm. long. The 

 form and mouth parts are much as in Ph. varicosa. There are three longitudinal lines of 

 tubercles on the back, two of which are fused into ridges, while those of the left-hand line 

 are mostly separate from one another. There are also twelve lateral groups of ridges, running 

 inwards from the mantle edge, one anterior, one posterior, and five on each side. The ground 

 colour is blackish, and the tubercles and ridges dirty white, perhaps representing blue and 

 yellow in life. The foot and the rhinophores are yellowish. The animal is undoubtedly a 

 Fryeria, and allowing for the variability of markings so common in this family corresponds 

 fairly well with Bergh's description of Fr. Ruppellii. 



Gen. Pliyllidiopsis Bergh. 



External appearance much as in Phyllidia but the tentacles are not free but attached 

 along their entire length. The buccal ajjparatus resembles that of Doridopsis, that is to 

 say it is not involved in a glandular mass. The oral pore gives entrance to a fairly \dde 

 chamber with laminated walls, into which opens the anterior portion of the alimentary tube 

 which is cylindrical and receives two small salivary glands. Beneath it is a single gland 

 probably corresponding to the ptyaline gland of other Nudibranchs. 



27. Phyllidiopsis stHata 1 



One specimen from Haddumati Atoll, Maldives, 40 /. Mouth parts as described above. 

 The upper surface of the preserved specimen is blackish, with three white lines do'wn the 

 centre and two white patches one at each extremity. Near the edge are some irregular 

 white markings. There are no tubercles or ridges. The foot and branchiae are somewhat 

 lighter than the back. The form is long and nan-ow, 1"4 cm. by 5 mm. broad and very flat. 



The markings of this specimen do not entirely correspond with Bergh's figure (Semper's 

 Reisen, xvi. Plate 84, fig. 23) of an individual captured by Moebius at the lie aux Fouquets, 

 Mauritius, but the differences do not seem sufficient to warrant the creation of a new species. 



CLADOHEPATICA. 



The Nudibranchiata Cladohepatica are characterized by the liver being ramified or at 

 least divided. The dorsal surface generally bears appendages, into which the ramifications 

 of the liver pass. As a rule, well-developed mandibles and a radula are present. In the 

 more specialized forms the latter is frequently reduced to a single row of teeth. There is 

 no blood-gland and only one spermatotheca. 



The numerically largest family of the Cladohepatica, which also shows all the character- 

 istics of the division in a typical form, is that of the Aeolididae, but there are a number 



72—2 



