420 
F. A. POTTS. 
aperture into pharynx sheath surrounded by eight fleshy 
rounded lips. The trepau of teeth marking the anterior end. 
of the chitinous lining is much reduced, the teeth being oidy 
represented by crenulations of the chitiu. No accessory 
tooth behind the trepan. 
Reproduction by collateral budding of stolons (for details 
see below). 
T. crosslandi is a well-marked species. It differs from 
most of the members of the genus (except T. zebra) in its 
small size, from all others except T. ingens in the structure 
of the ventral setee, the terminal piece of which has a smooth 
internal margin, without accessory tooth or pectinate edge 
(e.g. figs. 17 and 18 in PI. 23 bis), and from every species, as 
far as I know, in the great reduction of the cuticle and arma- 
ture of the pharynx. From the other three species which 
reproduce by collateral budding T. crosslandi is easily dis- 
tinguished by these and other points. 
Reproduction in Trypanosyllis Crosslandi. 
The chief difference from T. gemmipara is found in the 
absence of a genital appendage to the stock. 
Th ree individuals only were preserved, but this small 
series represents as many different periods of stolon-forma- 
tion, namely, the beginning of pi’oliferation, full maturity and 
cessation of activity. The following bi'ief descriptions may 
be given of the three forms : 
(1) A male individual with a small oval patch of pro- 
lifei’ating tissue on the ventral surface of the last two seg- 
ments. A vertical longitudinal section (Text-fig. 1) shows 
that the stolons are all in the first stages of development, 
that none as yet are segmented, though as many as nine rows 
have been formed, packed closely together. 
(2) Another male individual, with about 100 stolons of 
all sizes (PI. 23, figs. 8 and 9). The largest stolons were 
ready for detachment and amply provided with swimming 
setae. The area of proliferation is displaced to the right side, 
and the regular transverse rows of stolons described above in 
