vine: polyzoa of the wenlock shales. 
197 
18. Phyllopora tumida, Vine. Quart. Journ.Geol. Soc. May, 1885, 
p. 109, woodcut. 
Horizon and Locality : Caradoc beds : Wern-y-seadog, Llanfyllin. 
Range of variation: Under present circumstances and without 
having the lower Silurian fossils by me for examination, it w^ill be 
useless to make any further remarks on this point. It is much to be 
desired that existing material in private cabinets should be submitted 
to competent authorities for examination and description, for I 
believe that much good material is stowed too carefully away. 
19. PoLYPORA ? PROBLEMATICA, Vine, PL XII., figs. 23-24. 
=Polypora? problematica. Vine, Quart. Journ. Geol. Soc, 
Feb. 1882, p. 62. 
I am unable to add further to the description of this species as 
given above, but I have satisfied myself that the tpye is peculiarly a 
Silurian one, and I have not as yet seen any American species with 
which it can be associated. 
Localities: Buildwas and Tickwood beds. 
Family Thamniscid^. 
Thamniscidae, Vine, 4th Brit. Assoc. Rep., Foss. Polyzoa, 1883. 
Zoarium forming free dichotomising branches or pinnated fronds. 
Zoaecia on one side only, with from three to five (or more ?) rows of 
cell openings in a branch, occasionally having a smaller opening 
above or below the peristome of the cell. 
Genus Thamniscus, King. 
20. Thamniscus crassus Lonsdale's sp. 
= ? Hornera crassa, Lon. Sil. Syst., p. 677, pi. 15, figs. 13-13a. 
= ? Polypora crassa, Siluria, p. 215, Foss. Figs. 35, No. 1. 
,, crassa, Morris Catalogue. 
= Ceriopora, Salter, Cat. Camb. Foss. p. 100. 
= Hornera? crassa. Vine, Quart. Journ. Geol. Soc, vol XXXVIII. 
p. 60, figs 9-10. 
Horizon and Localities; Wenlock shales ; Wenlock limestone. 
21. Thamniscus delicatula, Vine. 
= delicatula, Vine, Quart. Journ. Geol. Soc, vol. XXXVIIL, 
p. 61. 
