On the Polyzoa of the St. Lawrence. 149 
This appears to be the species referred with doubt by Canon 
Tristram * to “ Psammomys tamaracinus, Kuhl,” but is 
certainly not the true Meriones tamaricinus, Pall., a very 
much larger and heavier animal. Its nearest ally is perhaps 
M. meridianus, Pall.; but neither that nor any other species 
with which I am acquainted has such a narrow slender skull, 
so little broadened posteriorly. Its small and narrow bull 
also distinguish it from all its allies, 
XXVI.— The Polyzoa of the St. Lawrence: a Study of Arctic 
forms. By the Rev. Tuomas Hincxs, B.A., F.R.S. 
[Plate VIIT.] 
[Continued from yol., iii. p. 433.] 
‘ Flustra solida, Stimpson. (Pl. VIII. figs. 1.) 
Flustra soda, Stimpson, Marine Invertebrata Grand Manan, 1858; 
Hincks, “ Polyzoa from Barents Sea,” Ann. & Mag. Nat. Hist. 1880, 
ser. 5, vol. vi. p. 282, pl. xv. figs. 2, 3. 
Eschara palmata, Sars, Beskriy. over nogle norske Polyzoer, 1862. 
Leta palmata, Smitt, Krit. Forteckn, ofver Skand. Hafs-Bryozoer, 
1867. 
Flustramorpha solida, Verrill, Proc. U.S. Nat. Mus. 1879. 
This very interesting species occurs amongst the St.-Law- 
rence dredgings; it was obtained off Bear Head, Anticosti, 
at a depth of 120 fathoms. Besides the form described by 
Sars a small variety was met with which presents some 
notable peculiarities, to which I shall refer hereafter. 
Zoartum erect, bilaminate, branched, attaining a height of 
about 3 inches, in the adult state composed of broad trans- 
versely separated segments, held together by epidermal tubu- 
Jar fibres, which traverse the surface of the zoarium and unite 
in their course downwards, so as to form cords of many strands, 
and ultimately give origin at the base to the fibrils by which 
the colony is attached to its site. Zowcia linear-oblong, 
narrow, and usually of great length, inclosed by strongly 
marked boundary-lines and perforated round the sides, very 
moderately convex, surface smooth, commonly invested by 
an epidermal membrane, orifice broader than high, upper 
margin very slightly arched, sides nearly straight, lower 
margin decidedly curved outward, an articular process at each 
* P. Z.S. 1866, p. 89. 
