192 vine: YORKSHIRE CARBONIFEROUS AND PERMIAN POLYZOA. 
seems to have overlooked the Yorkshire one. Even with Mr. Ulrich's 
beautiful figure before me (pi. Ixxi., and figs. 9 to 9c), I cannot help 
quoting from my paper again. One of the differences between 
certain of the American and Yorkshire forms may be noted. In 
some specimens of S. NicMisi, Ul., from Kaskaskia, there appears to 
be delicate ridges developed in parallel or wavy lines, which seem to 
separate the cells into parallel or waving rows, in other specimens, 
especially in the younger portions of the branch, that is in the apices, 
there are no ridges, and in this respect both the American and British 
forms agree."'" In the cancellated interspaces between cell and cell 
in the figured specimen of S, Nicklisi (pi. Ixxi., fig. 9a) there are 
two and three rows of punctures, varying in number, as a whole, from 
8 to 12 punctures below the cell mouth. In the Yorkshire example 
as figured, the punctures varied from five to seven or eight, while the 
cancellation below the orifice in Streblotrypa minuta, Vine, ( = S. 
Nicklisi, UL, var. minuta, Vine), though very faintly displayed in 
the fossils, vary from five to seven. Fortunately, however, one of 
my examples of S, minuta (pl.vii., fig. 8), from Gleaston Castle (Yore- 
dale Rocks, Lancashire), bear just below the bifurcatum of the branch 
a small ovicell which I seem to have previously overlooked, and this 
appears to me to justify my inclusion of the genus Streblotrypa in 
the family Hyphasmoporidce, rather than any other. The ovicell 
though not so large or so prominent on the surface of the Zoarium 
as in examples of Hyphasmopora, is still similar in character. The 
sac is rather more rounded, is situated just below the angle formed 
by a bifurcating branch, and the surface is faintly cancellated similar 
to the cancellation of the interspaces between cell and cell in the 
branch ; and the opening of the ovicell is on the right hand side. 
During a visit, some years ago now, that I had with Mr. John Young, 
of Glasgow, he showed me several examples of a Carboniferous 
species of Polyzoa which I regard as Htreblotrypa, and in all proba- 
bility many other examples would be found in our British rocks if 
more persistent research was made. 
There is one very remarkable species, Streblotrypa Hertzeri, Ul., 
in Mr. Ulrich's Waverley Bryozoa (p. 85, pi. xiv. fig. 8) which closely 
* Proc. Yorks. Geol. Polyt. Soc, vol. viii., p. 107. 
