Palceontologu of Upper Silurian Rocks, Victoria. 89 



Kunth/ Kayser,'- Liiidstroni,'^ Sherzer/ By others it has been 

 considered generally as a synonym of CyatJiophylliun. 



Undescribed forms of Pdraia are of pretty frequent occurrence 

 in the Upper Silurian of the Yass district, New South Wales, 

 which is considered to be of AVenlock age. 



The range of this genus is from the Upper Silurian to the 

 Carboniferous. 



Order — Monticuliporidea. 



Genus — Monticulipora, D'Orb., 1850. 



(Prod. Pal, i., p. 25). 



Sub-Genus — Monotrypa, Nicholson, 1879. 



(Palaeozoic Tabulate Corals, p. 320). 



Monotpypa, sp. ind. 



In the collection there ai-e three specimens preserved in lime- 

 stone from Mansfield, which, though unsatisfactory, prove the 

 presence of Monticuliporoids in these beds, but the internal 

 structure has been so destroyed by crystallisation that very few 

 details can be made out under the microscope. 



The corallites are small and irregular in size, prismatic, usually 

 four, five or six sided, and form a massive and probably globose 

 organism. The cell walls are thin and considerably thickened 

 with sclerenchyma. No trace of mesopores or acanthopores can 

 be seen, neither are monticules present in the specimens as 

 preserved, though in connection with this last point it must be 

 stated that it is doubtful that the true sui^face of the organism is 

 preserved. The tabulie are complete, far apart, thin, practically 

 horizontal, and in adjoining tubes almost opposite. 



There appeal's to be no differentiation of the corallites into 

 larger and smaller. 



Fi'oni these few points this form would appear to come closer 

 to Nicholson's Aloiiotrypa than any other sul)-division of Alonti- 

 ailipora. Though agreeing in many points with species recorded 



1 Zeits. deutsche Geol. Gesell., 1S70, xxii., p. 37-42. 



2 Abhand. Geol. Specialkai-te Preussen, 1878, ii., p. 231. 



3 Bihang K. Sv. Vet. Akad., 1SS3, viii., 9, p. 12 (separate edition). 



4 American Geologist, 1S91, vii., p. 278. 



