304 R. F. Tomes — British Cretaceous Madreporaria. 



and degree of development of the lamelliform columella, but differ 

 in having the tuberosities at the foot only feebly indicated, and the 

 ribs on the sides of the septa more strongly marked. I have 

 examined a considerable number of these small Plncosmilim from 

 Haldon, but they are merely siliceous casts, and so badly preserved 

 that had I not the advantage of a well-preserved specimen from 

 Blackdovvn for comparison, I should hesitate to speak decisively of 

 them, excepting to determine with absolute certainty their distinction 

 from the Gosau specimens o? Placosvdlia cimeiformis. Tiie latter are 

 perfectly distinct from the Blackdown and Haldon specimens. 



Trochosmilia sulcata, Edw. & Haime : Brit. Fos. Cor., 1850, 

 p. 68, pi. ii, fig. 6. 

 I notice this species only to record its great rarity, one specimen 

 alone amongst several hundreds from the Gault at Folkestone having 

 reached me ; and I maj^ make the same observation respecting the 

 extremely pretty Leptocijnthus gracilis,^ a single specimen being all 

 that has appeared. 



Parasmilia granulata, Duncan : Supp. Brit. Fos. Cor., 1869, pt. ii. 

 No. 1, p. 13, pi. vi, figs. 5-8. 



The present species was founded on one or more specimens in the 

 Dixon Collection, but as no indication of locality has been made 

 known, I take the opportunity of recording some examples which 

 were in the collection of Dr. Wright and came to me labelled in his 

 handwriting, " Monocarya centralis, W. C. Brighton." They accord 

 well with the figures and description given by Professor Duncan, 

 but one of them is of greater size than the types, having a height of 

 1 inch 4 lines and a diameter of calice a little exceeding 10 lines. 

 It has the largest calice of any British Parasmilia I have yet seen. 



Paras3iilia Mantelli, Edw. & Haime: Brit. Fos. Cor., 1850, p. 49, 

 pi. viii, fig. 2 ; Hist. Nat. Cor., 1857, tom. ii, p. 173. 



The original describers of this species had access to one specimen 

 only (from Bromley in Kent) when diagnosing the species, and 

 Professor Duncan does not appear to have seen a single specimen 

 even, but was of opinion that it was only a variety of Parasmilia 

 Gravesana, which he reduced to the rank of a subspecies. By the 

 kindness of Dr. Blackmore, of Salisbury, who has favoured me with 

 a number of Parasmilice from the Chalk near that town, amongst 

 which are several specimens of Parasmilia Mantelli, I can without 

 hesitation restore the species to its former place. There can be no 

 doubt as to its distinctness from Parasmilia centralis and P. Gravesana, 

 and, indeed, from all the other Britisli species of the genus ; but 

 I must make an addition to the otherwise very exact description of 

 MM. Milne Edwards and Haime, and note the existence of a very 

 large and rather elaborately developed columella, which attains in 

 one specimen to quite one-third of the diameter of the calice. 



1 Duncan: " Supp. Brit. Foss. Cor.," pt. ii (1870), No. 2, p. 34, pi. xiii, figs. 5-8. 



