BY T. HARVEY JOHNSTON AND 0. W. TIEGS. 227 



producing apparatus partly incorporated in the female tissues. 

 Complete fusion would produce a hermaphrodite condition, but 

 we do not think it likely that hermaphroditism would arise in 

 that way, since the male system would require to retain at least 

 a part of its own nerve system for its innervation. 



The outstanding features of the remarkable species now de- 

 scribed may thus be summarised : — Female : Bonellia-like form; 

 the presence of two to four setae; two well developed and func- 

 tional uteri; simple anal glands opening directly into the rectum, 

 i.e., there are no definite anal vesicles ; posterior transverse 

 position of ovary; a siphon associated with the intestine; presence 

 of an invagination (andrcecium or male tube) within which only 

 one male is lodged. Male: extremely degenerate and apparently 

 partly fused with the female; possessing two functional vesicula? 

 seminales; hooks absent. Such features are of sufficient import- 

 ance to justify the erection of a new genus, Pseudobonellia, within 

 the family Bonelliidce, with generic characters as above stated. 

 Type species, P. biuterina Johnston and Tiegs, 1919. 



The form of the body and proboscis, as well as many of its 

 internal characters, separate the genus from Thalassemia and 

 Hamingia, but relate it to Bonellia; while the presence of two 

 uteri, a male tube and a siphon in the female, and two vesiculse 

 in the male separate it from the last-named. The absence of 

 hooks or ventral setae in the male has been noted in the case of 

 some species of Bonellia, while the presence of more than two in 

 the female has been recorded in the case of one species, viz., B. 

 miyajimai, by Ikeda (1907, p. 3, PI. 2, fig. 6), who reported the 

 occurrence of no less than twenty-nine small ones. 



Typical specimens of P. biuterina are being deposited in the 

 Australian Museum, Sydney, and the Queensland Museum, 

 Brisbane. 



LITERATURE. 



Dakin, W. J. — The Marine Biology of West Australia. Proc. Roy. Soc. 



West Aust., i., 1914 (1916), pp,ll-27. See also Journ. Linn. Soc. 



Lond., xxxiv., 1919, p. 175. 

 Haswkll, W. A. — An Australian species of Bonellia. Proc. Linn. Soc. 



N. S. Wales, Ser. 1, x., 1885, pp. 33 1-2. 



