342 



A. W. WATERS ON FOSSIL CHILOSTOMATOTJS 



Schreibersi, Ess., with which Mr. Woods compares it ; and, further, 

 the two prominent avicularia are wanting ; but from my Val-di- 

 Lonte specimens of C. Schreibersi I find that both belong to the Schi- 

 zoporellidse, and are allied in many particulars. 

 Loc. Muddy creek, Western Victoria (W.). 



64. Eetepora marstjpiata, Smitt. Plate XV. figs. 34, 35, 36 ; 

 Plate XVII. figs. 59, 61, 76, 77. 



Eetepora marsupiata, Sm. Floridan Bry. p. 67, pi. xiii. figs. 245- 

 254 ; Svenska Vetensk. Handlingar, vol. xi. 1872. 



PhidolopJwra labiata, Gabb & Horn, " Polyzoa of Second, and Tert. 

 Form, of N. Amer." p. 138, pi. xix. fig. 21 (Journ. Ac. Nat. Sci. 

 Philad. vol. v. pt. ii.). 



Zoarium reticulate. Zocecia suboval to hexagonal, separated by 

 a distinct raised border ; peristome elevated in young cells ; in old 

 ones the aperture is immersed, with sometimes a spine on each side 

 of the aperture ; in front of the peristome a ridge, at the base of 

 which is sometimes a small pore (sometimes avicularian) ; this gives 

 a distinctly sinuated appearance to the peristome : in some speci- 

 mens large, erect, angular avicularia in the middle of the zooecium ; 

 in others large erect more spathulate avicularia ; in others very long 

 and very narrow immersed avicularia in a similar position, with the 

 mandible in all cases pointing directly or diagonally downwards ; 

 sometimes there are small rounded avicularia pointing downwards, 

 with a central pore. Surface smooth, or with few granulations ; often 

 two large pores near the proximal extremity of the zocecia. One 

 ovicell is subimmersed, with one cleft, as described by Smitt ; ano- 

 ther is more raised and more globose, with two depressed lines close 

 together instead of the one central cleft ; and there is also a small 

 boss on the centre of the ovicell. The dorsal surface, which is 

 divided irregularly by thin raised lines, has minute rounded avicu- 

 laria scattered about; there are also long, triangular, immersed 

 avicularia and large erect ones. In the basal portion the aperture 

 is depressed, when we find the structure figured in figs. 59, 61 4 

 and 7 6, which are drawn from different specimens ; but interme- 

 diate ones leave little doubt as to their identity. 



In these we see the median pore representing avicularia, and 

 showing the relationship to Porina. Median pores are known in 

 Retepora tuberculata, Ess. Some of the basal branches seem to show 

 that reticulation was much less frequent than in most Reteporm ; and 

 this and R. rimata would be Psilescharce of Busk, a genus which 

 cannot be retained. * 



It is impossible to be quite sure if this is the same as the fossil 

 described by Gabb and Horn. It is evidently allied to R. Beaniana, 

 King, and probably is the species described under that name by 

 Stoliczka. The suboral pore represents the suboral avicularium in R. 

 Beaniana ; and small avicularia are found on the front of Beaniana. 



Loc. Living: Floridan seas, 16-262 fathoms (Sin.) ; Teneriffe 

 (Bush). Fossil: Miocene, S. Barbara, Amer. (G. Sf H.); Mount 

 Gambler (Lond. GeoL Soc. coll.). 



