306 JOURNAL OF CONCHOLOGY, VOL. II, NO. 10, APRIL, I906. 



form of the penis. As in the Pacific specimens it is enclosed in a 

 bag, situated under the right rhinophore, and connected with the 

 female branch by a thin duct which is partly embedded in the body 

 wall. The bag contains not only a soft conical organ as in the 

 Pacific specimens, but also attached to it a thick strong convoluted 

 tube 10 mm. long. 



It would appear that this species should be called L. sieboldi, not 

 olivacea, since if Rafinesque's description is set aside, Krohn's specific 

 as well as his generic name must hold good. 



Lobiger. 



This genus is easily recognized externally by its remarkable wing- 

 like swimming lobes, which give it somewhat the appearance of a 

 dragon-fly. The shell is flatter than in Lophocercus, and the foot 

 broader. The internal anatomy of the two genera is much the same, 

 exce[)t that in Lobiger the buccal crop is very large and elongate, the 

 salivary glands racemose, and the teeth bear three minute denticles 

 at the tip. 



Five species have been described : L. serradifaki or philippii, L. 

 soitverhii, L. viridis, L. nevilli, and L. zvihoni} Some details respect- 

 ing the synonymy, etc., are given by E. A. Smith," who states that 

 the types in the British Museum show that Z. pellucidus is not a 

 separate species. L. souverbii Fischer from the West Indies is said 

 to be characterised by having only two swimming lobes, one anterior 

 and one posterior ; and Pilsbry has proposed a new subgenus for it, 

 Dipterophysis. But as Lobiger is known sometimes to cast off its 

 lobes, it is eminently probable that. this species was founded on a 

 mutilated specimen. L.wilsoni T3i\.e from South Australia is possibly 

 a valid species, though imperfectly described. It is of a pale green 

 colour, with oblong rounded lobes, and a very narrow, pointed, smooth 

 tail. L. pictus Pease (or L. viridis Pease, for he seems to have called 

 it by both names) is described and figured as having four tentacles 

 and has been mnde the type of a subgenus Pterygophysis by Fischer.* 

 Some authors have regarded this form with scepticism, and it must 

 be admitted that Pease was often inaccurate, but it is noticeable that 

 Pelseneer* describes and figures L. philippii as having two pairs of 

 tentacles, and the prolongation of the lips into buccal tentacles does 

 not imply any great morphological change. Pease's account may, 

 therefore, prove correct. G. and H. Nevill described very imperfectly 

 a form from Ceylon under the name of L. vi'idis, which was altered 



1 L. corneus Morch seems to be a name without a description. 



2 " Notes on the genus Lobiger," Ann. Mag. Nat. Hist. (6), vol. 3, p. 308-311, Apr., 1889. 



3 "Man. de ConchyL," p. 571. 



4 " Rech. sur divers Opisthobranche.s," p. 19, 1693. 



