180 
HETER0P0EID2E. 
its successors may be due in part to our ignorance of tbe Eryozoa 
from the Trias, but the gap is so great that as a matter of 
convenience it may be advisable to separate the Mesozoic forms 
as a distinct family. 
Among the names applied to this family the Crescisidae of 
d’Orbigny has long priority. That family was founded in 1854* * 
for eleven genera, of which Omniretepora included a Silurian species 
{Sornera crassa, Lonsd.^) from the Wenlock Limestone ; but the 
other ten genera are a homogeneous group, and may be included 
in the two genera Heteropora and MuUicrescis. 
Five years later Eusk^ placed Heteropora with six other genera, 
including such varied fossils as Neuropora, Alveolaria^ Spiropora^ 
Fungella, and Stellipora, in a family, the Cerioporidae. This 
artificial group has no claim to recognition. 
In later years Heteropora was assigned a very different position, 
owing to the Petaloporce^ which had been included in it, being 
adopted as the type of the genus. Thus Marsson^ used Seteropm'a 
for three species of Petalopora, and therefore separated the genus 
far from the Ceriopora group and included it in the Entalophoridae. 
Pergens & Meunier^ had just before founded a family Hetero- 
poridae, and referred to it Heteropora poly taxis (Hag.) and 
Heteropora suhstellata (d’Orb.) ; but, unfortunately, M. Pergens 
subsequently followed Marsson, and described ® Heteropora as 
only “formes dHntalophora, chez lesquelles s’est effectue un 
grand depot de calcaire, avec de fortes cavites intersquelettiques.” 
He, however, included in Heteropora such species as arhorea, 
K. & H., variahilis^ d’Orb., michelini, d’Orb., and constantly 
which do not answer to this description, as well as species of 
Claviclausa. 
Hamm,”* on the other hand, had taken the massive species of 
Heteropora as the type and retained the genus in his family 
Cerioporidea. 
* Bry. Cret. p. 1063. 
2 In Murchison. Silurian System, pi. xv. fig. 13. ’ 
^ G. Busk. Crag Polyzoa, 1859, p. 91. 
* Th. Marsson. Bry. Riigen : Pal. Abh. 1887, vol. iv. pp. 25-6. 
® E. Pergens & A. Meunier. Bry. gar. Faxe : Ann. Soc. malac. Belg. 1887, 
vol. xxi. (1886), p. 223. 
® E. Pergens. Rev. 1890, p. 357. 
H. Hamm. Bry. mastr. Ob. -Sen. i., Cycl. 1881, p. 34. 
