384 



G. R. VINE ON THE FAMILY DIASTOPOKID^i. 



1. Diastopoea stomatopoeides, mihi. Plate XIX. figs. 1-10. 



ID. liasica, Quenstedt, Handb. der Pebref. p. 637, pi. lvi. fig. 10. 

 ? D. crussolensis, Dumortier, Palaeont. Studies, p. 226, pi. xlviii. 

 figs. 10 & 12. 



Zoarium subcircular or orbicular, sometimes indefinite in its mode 

 of growth, forming small isolated patches on shells or corals, varying 

 in breadth from one and a half to three lines. Zooecia arranged 

 linearly, or nearly so, long and slender tubes, many of them 

 wrinkled or surface-roughened, and adherent by their whole length ; 

 orifice, when perfect, oval, rarely circular. Primary zooecia either 

 very excentric in the larger colonies, or proximal in the smaller 

 ones, which soon become excentric as the colonial growth increases. 

 Ocecia rare, when present pyriform, involving at least two of the 

 cells. Zooecial tubes very faintly punctate. 



Hah. On Anion, cornucopia?, Up. Lias, Bloxham ; on Cardinia 

 hybrida, Sow., Appleton ; and on Montlivaltia Victoria, Mid. Lias, 

 zone of Amm. Henleyi, Cherrington, Oxfordshire ; Sup. Lias, Crussol, 

 Dumortier ; on Amm. jurensis, in zone of ditto, Southern Germany, 

 Quenstedt. " Deeper than this," says Quenstedt, " I have never 

 found it." 



A careful study of the figures given will convey to the palaeon- 

 tologist a very fair idea of the character of this very early Mesozoic 

 type of Diastopora. Unlike any of the palaeozoic types, it seems to 

 be persistent, so far as the character of the cell is to be relied upon, 

 high up into the Oolitic series, and, but for the peculiarity of its 

 habit, might be recognized in the Stomatopora diastoporides, JSTorman, 

 and the Tubulipora lohulata, Hassall *. Indeed, of the first of these 

 species Mr. Hincks says " that it is the largest of British Stoma- 

 topora?, and has very much the look of Diastopora and of the 

 other species, " I can see no sufficient ground for placing Tubuli- 

 pora and Diastopora in separate families ; the two genera are nearly 

 related, and have many common characters." He said this without 

 being aware of the existence of the forms now figured and described, 

 which are in every sense confirmatory of the justness of his family 

 arrangement. 



In the Oolitic series, beginning with the lowest beds — the Pea- 

 Grit of the Inferior Oolite — we recognize altogether different types, 

 not widely separated, but even on the same blocks. These types 

 belong to the foliaceous as well as to the crustaceous forms ; and 

 where to draw the line between the two it is difficult to say. In 

 some few cases the boundary lines are broken down ; and one at least 

 of the typical Diastopora? pass from the crustaceous into the foli- 

 aceous form by a series of quiet gradations. Mr. Longe has given 

 more attention to these forms than I have ; and his remarks on these 

 peculiar species may be referred to for exact information f . After 



* Figures and description in Hincks's Brit. Polyzoa, vol. i. pp. 434 & 444, 

 pis. 61 & 63. 



t Geological Magazine, January 1881. 



