ON FOSSIL POLTZOA. 251 



the first or second cell of the branch, which in tux-n forms the base of a 

 new branch ; cells generally uniform in size, sometimes swelling towards 

 the distal extremity ; older cells slightly rugose, or granular ; oral 

 extremity raised at times with circular or semi-circular orifices ; two 

 cells average from three-quarters to one line in length. 



Locality, 8fc. — Lower Mid. Lias, Fenny Compton, on Gryi}liCBa incurva. 

 Cabinet of Mr. Walford. {Aledo dichotoma. Beesley.) 



Stomatopora dilatans montUvaltaformis (new variety). Zoarium, 

 adherent, slightly ramified, consisting of short stem of nniserial zocecia, 

 Avhich gradually widens so as to form dilated branches, but of very 

 irregular form. Zooeoia, punctate, depressed ; orifice circular, slightly 

 raised ; cells passing from uni- to tri-serial, and each cell measuring 

 about half a line in length. 



Locality. — Lower Mid. Lias, Cherrington. 



Habitat. — On Montliualtia Victoria. — Cab. Mr. Walford. 



The peculiar habit and cell-character of this type is so distinct from 

 the former, that, after many grave thoughts, I have decided to give it the 

 above name. On the same coral are specimens of Diastopora. 



Stomatopora Waltoni, J. Haime. 

 (pi. vi. fig. 3, Haime). 



This species is found adherent to specimens of Biastopora from the 

 Bradford clay, and also from the Cornbrash of Stanton. It assumes 

 many peculiar habits, but the cell-arrangement generally is a rather con- 

 «tant feature. Sometimes it approaches the character of 8. diclwtomoides, 

 D'Orb., at other times that of the recent 8. gramdata, M.-Ed. To the 

 latter species Hincks' assigns a remote ancestry, and it is a difficult 

 matter to say nay to his synonyms, and range in time, as all the nniserial 

 Stomatoporce may be closely related. My own specimens from the Green- 

 sand are too fragmentary to allow of a very close comparison. 



Localities, ^'c. — Approaching 8. dlchotomoides, D'Orbigny's type, Great 

 Oolite, Kidlington. Adherent to Terebratida maxillata. Cabinet of Miss 

 Gatty. 8. Waltoni type, Bradford Clay, and Cornbrash, Bradford and 

 Stanton, Wilts. My own cabinet. 



In our modern classification (Hincks) we have a sub-genus, Proioscina, 

 which links together the genei'a 8tomatopora and Tnhulipora. Haime's 

 second genus is also called Prohoscina, but there seems to me to be a great 

 diflference between the recent and fossil species. The type of the recent 

 sub-genus 8tomatopora incrassata, Smitt, is a very peculiar species as 

 regards the cells, and I know of no Jurassic type that can compare with 

 it. The type of Haime's genus is the Cellepora echinata, Munster or 

 Goldfuss. This latter species is a Tertiary type from Astrupp, and I fail 

 to recognise any species in the British area that can compare with this 

 either. Seeing that D'Orbigny applies the term Prohoscina and Idmonea 

 indifferently for certain species ; that Busk places the sub-genus with his 

 Alecto ; and that Hincks practically disallows the division, it seems to 

 me only a matter of very questionable convenience to retain it. There 

 are, however, certain as yet undescribed types in both the Inferior and 



' Brit. Marine Polyzoa, vol, i. p. 426. 



