24 Prof. P. M. Duncan on the 



Fiy. 81. Mucrotiella spino-sisswia , MacG. Aperture, showing denticles, 



X 50. 

 Fig. 32. Mucronelln diaphana, MacG. Aperture, showing denticles, x 50. 

 Fiq. 33. Mucronelln Peachii, Johnst. Aperture, showing denticles, X 50. 

 Fi(f. 34. Smittia Napicrii, Waters, X 25. 

 Fig. 35. The same, X 85. 



Figs. 36, 37. Exochella longirostris, Jullien, X 85. 

 Fig, 38. Mucronella variolosa, Johnst., X 50. 

 Fig. .39. Smittia Sinittiana, Busk. Aperture, X 50. 



II. — On the Cretaceous Species of Podoseris, Dime. 

 By Prof. P. Martin Duncan, M.B. (Lond.), F.K.S., &c. 



[Plate v.] 



Contents. 



List of old and new Species. 



Keconsideration of the old and Description of the new Species. 



Young Forms of Podoseridne. 



Remarks upon some Morphological Details. 



A VERY interesting collection of Corals, numbering nearlj 

 140 specimens, has been entrusted to me by Thomas Jesson, 

 Esq., F.G.S., who obtained them from the Red Clialk of 

 Norfolk. The species do not assist the stratigraphical 

 geologist in fixing a definite horizon for that interesting Cre- 

 taceous deposit. They are all members of the genus of 

 Lophoserine Fungida which I established in 1869, under the 

 name Podoseris (Pal. Soc. 1869, Monogr. Brit. Fo.-^. Corals, 

 2nd ser. pt. ii. no. 1, p. 25) *. The species have not been 

 found away from the Red Chalk. The great variability of 

 the species of this genus was noticed in the essay which con- 

 tained the generic diagnosis, and it is very evident after 

 examining* the collection lately received. The species P. 

 elongata and P. mamilliformis have some very remarkable 

 varieties, which are now described, and it is satisfactory to 

 find amongst Mr. Jesson's treasures a perfect and unworn 

 specimen of the last-named species. The diagnosis of both 

 of the original species requires slight modification, and it is 

 advisable to add some new species to the genus. 



* The genus was considered during the publication of the " Revision of 

 the Madreporaria " (Journ. Linn. Soc, Zool. 1884, vol. xviii. p. 153), and 

 it was placed in the Podoserioida, an alliance of Lophoserines. It has of 

 course no affinity with Jt/iizavgia, Ed. & IL, as has been suggested. 



