STOLON FOEMATTON IN SPECIES OP TRYPANOSYLLIS. 419 
Teypanosyllis Crosslandi SP.n4 
This was obtained in the harbour of Wasin, Zanzibar. The 
following account of its occurrence and appearance is com- 
piled from Mr. Crosslaud’s notes. In colour it is a bright 
orange-red ; the four eyes are brown. The stolons are of the 
same colour as the stock. In life, Mr. Crossland i-emarks, 
their tails keep waving- in the water, but whether this is 
because of muscular movements of the stolons themselves 
preparatory to detachment from the stock, or is merely due 
to the currents in the water, he does not make clear. The 
animal appears to live in a red sponge. 
Diagnosis. 
Length, 22 to 25 mm. Breadth, 3 mm. (including setm). 
Number of segments, 125 to 135. 
Try panosyllis of small size and number of segments. 
Colouration as above. Prostomium (PI. 23, fig-. 7) small, not 
distinctly bilobed, but tripartite ; eyes i-aised on slight conical 
elevations, which coalesce in case of front pair. Two pairs of 
eyes, arranged almost in a square, but posterior rather wider 
apart and more minute. Median and lateral tentacles about 
the same length, with fifteen or so annulations. Dorsal cirri 
slender, alternately long and short, with unusually long nn- 
jointed base, succeeded by thirty to forty annulations in the 
case of the longer, and twenty to twenty-two in the shorter, the 
whole sometimes longer by one third than the breadth of the 
body. Parapodia (PI. 23 bis, fig. 19) acuminate, apex occupied 
by three short acicnla, and below these eight to twelve stout 
compound setae. In these the terminal piece, with incurved 
apex, has a smooth internal margin ; shaft below provided with 
short processes, giving a pectinate appearance (PI. 23 bis, 
fig. 18). 
Pharynx lined by a very thin chitinous tubular lining; the 
* Named after my friend Mr. Cyi-il Crossland, Clare College, Cam- 
bridge, and now Biologist to the Red Sea Pearl Fisheries, who collected 
this and many other interesting forms at Zanzibar in 1900-1. 
