190 
vine: polyzoa of the we^'lock shales. 
Busk, Hincks, and Waters in describing Diastopora. Under these 
circumstances it seems to be useless to increase the difficulties of our 
abeady too much encumbered nomenclature by furnishing two names 
for one group. In Diastoporella the difference between Diastopora is 
recognised, and as this is a well-marked Silurian genus I have en- 
deavoured to give it prominence by a full description. The Entalo- 
phora, too, are different from later forms, but this will be pointed out 
when describing the paleozoic species. 
The Mitoclema of Ulrich, as pointed out by the author* bears 
considerable resemblance to the mesozoic and recent genera Spiropora 
Lamx, and doubtless belongs to the same family of Bryozoa," and he 
seeks to establish i\Iitoclema because there is a difficulty in carrying 
over the well known Jurassic forms to make them serve as generic 
types for palaeozoic species. Mr. Waters,! however, differs in his 
appreciation of Paleozoic Entalophora, for he considers that Mitoclema 
cinctosa, Ulrich can only be regarded as a synonym, for he thus 
places it in his list under Goldfuss' well known Entalophora verticil- 
lata. But my own experience goes to show that there are the same 
difficulties to grapple in dealing with the Palaeozoic Entalophora as 
with the Diastopora. I cannot, however, speak with authority 
respecting Mitoclema cinctoso for I do not know it otherwise than by 
figure and description. 
Genus Diastoporella, Vine. 
Diastoporella, Vine. Brit. Assoc. Rep. Foss. Polyzoa III. 1883. 
Zoarium encrusting, rarely circular. Zo?ecia tubular, elongate, 
contiguous arranged in regular series; cell mouths circular, with well 
fomied peristome, and occasionally slightly less than the diameter of 
the cell. 
10. Diastoporella consimilis, Lonsdale. PI. XII., figs. 8-18. 
Aulopora consimilis, Lonsdale Silurian System, p. 1567, pi. 15, 
fig. 7. 
Reproduced as pi. xli. Siluria Ed., 1859, Marked 7 Diastopora 
? consimilis, "probably a Bryozoon." 
*Jourii. Cincin. Soc.Nat. Hist, Oct. 1882, p. 159. 
t Quart. Journ. Greol. Soc, vol. 40, p. 685. 
