VINE : CLASSIFICATION OF THE PALAEOZOIC POLYZOA. 
37 
party, and in these notes I have done my best to be fair all round. 
If, then, I take two horizons of Mr. Hall's, which have been fully 
catalogued, the Upper and the Lower Helderberg groups, I shall be 
able to give a pretty full synopsis of the generic, but not the family 
grouping of the author. 
Lower Helderberg Group.* =Upper Silurian. 
Of the grouping in this horizon Mr. Hall says " The fossils in 
this enumeration are designated as Corals and Bryozoans, the line of 
demarcation between the two classes in the genera Ch^tetes, Trem- 
atopora and Callapora being at the present time not satisfactorily 
determined." Mr. Hall further states that the revision of his previous 
paper (1874), together with the description of the 
new species here 
included, gives an expression of our knowledge of these groups of 
fossils up to 1878. 
Genus Aulopora, Goldfiiss Five species. 
„ Vermipora, Hall Three 
)) 
,, Striatopora, Hall One 
>» 
Michelina, De Koninck One 
>> 
,, Favosites, Lamarck Six 
„ Chaetetes, Fischer Six 
j> 
The whole of these genera are described as 
"Corals" by Mr. 
Hall, and the following as "Bryozoans." 
Genus Trematopora, Hall Nine species. 
,, Callopora, Hall Thirteen 
5) 
„ Lichenalia, Hall Three 
>> 
„ Ceramopora,t Hall Four 
>> 
„ Paleschara, Hall Three 
5> 
,, Stictopora, Hall One 
)> 
„ Escharopora, Hall Four 
>) 
„ FenestellaJ Lonsdale Twenty-five 
,, and Vars. 
,, Icthyorachis, M'Coy One 
>> 
,, Thamniscus, King Five 
>> 
* 32nd Annual Report on the State Mus. Albany, 1 880. 
f This includes Berenicea maxima, Hall, 26th Rep , N. Y. S., Mus., 1874. 
+ Including the so-called " Hemitrypa " species. 
