94. rErort—1868. 
(Order ZOANTHARIA APOROSA.) 
Family OCULINID. 
Genus Drenasus, Lonsdale. 
This genus was established by Lonsdale in Dixon’s ‘Geol. of Sussex,’ 
1850, and was described by the learned zoophytologist with all that critical 
acumen which characterizes him, pp. 248 to 254, pl. 18. figs. 14 to 28. 
MM. Milne-Edwards and Jules Haime, whilst they acknowledge the genus 
to be “ voisin des Synhelia” (Hist. Nat. des Corall. vol. 1. p. 115), do not 
give it a place in their classification. I have therefore carefully studied and 
drawn the specimens from the Dixon Collection in the British Museum, and 
have great pleasure in doing justice to Mr. Lonsdale, by inserting his 
genus with slight alterations to meet the present terminology. 
Genus Diblasus, Lonsdale (amended). 
The corallum is incrusting, very irregular in shape; the calices are wide 
apart and projecting ; the intercalicular tissue is costulate. The septa are un- 
equal. There are no pali, The columella is formed by the junction of the 
larger septa, and does not exist as aseparate structure. Gemmation marginal 
and intercalicinal. The genus is evidently not closely allied to Synhelia ; for 
it has no palular or true columellary structures. It approaches the genus 
Astrohelia, which is a transition genus bringing the Oculinide in relation with 
the Astreinw through the Claudangie (Milne-Edwards and Jules Haime, 
‘Hist. Nat. des Corall.’ vol. i. p. 111). 
Diblasus Grevensis, Lonsdale. 
The corallum is very irregular in shape and size. The calices project, and 
are irregular in their projection and size. The coste are granular, equal, 
subequal, and unequal in different parts of the same corallum. ‘The septa 
are in three cycles, and are unequal and dentate ; the primary reach those 
opposite, and form a rudimentary columella; they are crowded, and are 
granular laterally. Diameter of usual-sized calices 4 inch. 
Locality. Gravesend Chalk. 
In the British Museum, Dixon Collection. 
The condition in which the specimens of this species is found is very 
remarkable: the inside of nearly every calice has been worn away, so that 
the mural edges of the septa are all that remains of them; the perfect 
calices appear to have shrunk from the surrounding ccenenchyma; and in 
many places the costz have been worn off. 
Lower Chalk. 
There are several specimens of corals from the Lower Chalk; but I 
have not been able to identify them, on account of their fragmentary con- 
dition. Onchotrochus serpentinus is a Lower-Chalk form. 
Fossil Corals from the Upper Greensand. 
The following authors have written on this subject :—W. H. Smith, ‘ Strata 
identified by Organic Fossils,’ 1816. Godwin-Austen, Trans. Geol. Soc. 2nd 
Series, vol, vi. p.452. Morris, ‘ Cat. of British Fossils,’ p. 46 (1843). MM. 
Milne-Edwards and Jules Haime, op. cit. 
The scanty Coral-fauna of this deposit was described by MM. Milne- 
Edwards and Jules Haime; and although some years have elapsed since the 
publication of the first part of the ‘ British Fossil Corals’ (Pal. Soc.), and the 
beds have been well searched, very few additions can be made to the list: of 
fossils. 
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