190G.] TURBELLARIA OF THE THIRD TAN'GAXYIKA EXPEUITIOX, 777 



Collected 4 July, 1906, by G. C Shortridge, and presented by 

 Mr. W. E. Balston. 



The range of the beautiful grey M. albocinereus on the mainland 

 of Western Australia is as yet quite unknown, all the recorded 

 specimens being from one restricted area. 



47. Mus MuscuLus L. 

 Male and female. 



48. Perameles bougaisvillei Qaoy &, Gaim, 



An imperfect skull, jiicked up. 



Owing to the probable extermination of this species in Bernier 

 Island, and the fact that we have no specimens at all from Shark's 

 Bay, whence the species was originally described, this skull, 

 impei'fect as it is, is of much value to us. 



It indicates, as in the case of the other Shark's Bay animals, 

 that this Bandicoot is diffei-ent from the one found fui-ther south, 

 to wliich Wagner's name rjiT/osiiros will be applicable. 



The chief difference observable is in the size of the teeth, 

 the combined length of the thi-ee anterior molariform teeth of 

 hougainvillei being only 9 mm., while in raijosaros they measure 

 10-10-5 mm. 



?). Zoological Results o£ the Third Tancranyika Expedition, 

 conducted by Dr. W. A. r'unning-ton, 1904-1905. 

 Report on the Turbellaria. By F. F. Laidlaw. 



Tteceived July 12, 1906.] 



(Text-figure 126.) 



[The species of Turbellarian described below by Mr. Laidlaw 

 was the only one observed dming the Expedition. Specimens 

 were collected at Niamkolo, at the south end of Tanganyika, and 

 at Xdanvie, near the north end, but the species was observed at 

 several other localities. The specimens were taken on the under 

 side of stones in shallow water. — W. A. C] 



Plaxaria taxgaxyik.e, sp. n. (Text-fig. 126.) 



A small species. Length of the largest spirit-specimen about 

 8 mm. Breadth 3 mm. 



Anterior end rather pointed ; eyes ifi.e,) moderately distant, 

 lying in front of the level of the pair of auricles {ait.). Body (of 

 sjjirit-specimen) rather oval, the hinder end pointed. Pharynx 

 opening {ph') a little in front of the commencement of the hinder 

 fourth of the body, at the level of its greatest width. The colour 

 is black in the larger specimens, grey-brown in the smaller. The 

 ovaries lie at the hinder end of the first fourth of the body. The 

 oviducts were not seen. The uterus (?.6i.) is symmetrical and lies 



52* 



