XXIV 



A MONOGRAPH OF THE 



Gen. 48. Placobranchus, Van Hasselt. Tentacles 4, back with 2 lateral 

 membranous expansions, having their upper surface covered 

 with folds. Tongue? ......'•. 



TPVE. 



P. ocellatus, Rang. 



Fam. 16. Limapontiada. 



Gen. 49. Acteonta, Quatref. Tentacles 2 flattened lobes at the sides of 

 the head, produced behind into points; sides of the back with a 

 tubercular ridge in the region of the anus. Tongue, a single 

 plate with a large broad spine, A spinous buccal collar 



Gen. 50. Limapontia, Johns. Tentacles wanting ; sides of the head arched 

 and carinated; back plain, without appendages. Tongue, a 

 single plate with a large br^d spine. A spinous buccal collar L. nigra, Johns. 



A. senestra, Quatref. 



Tribe 2. Body cylindrical or compressed. 



Fam. 15. Phyttirrhoidce. 



Gen. 51. Phyllirrhoe, Peron. Tentacles 2, long; tail truncated. Tongue, 

 a single central plate with numerous denticles 



P. Bucephala, Peron. 



