322 



A. W. WATERS ON EOSSIL CHILOSTOMATOUS 



short, laterally subcircular, compressed. Zocecia quincuncially ar- 

 ranged, hexagonal ; oral aperture arched above, lower lip straight, 

 with two distinct denticles, aperture placed one third the length of 

 the area from the top ; zocecial area slightly depressed. 



This differs from Cellaria (Escham) aspasia, d'Orb. (Pal. Fr. 

 p. 132, pi. delxvii. figs. 14, 16), in having the cells distinctly hexa- 

 gonal instead of spatuliibrm, and from Melicerita angustiloba, Busk, 

 in having the cells arranged quincuncially instead of in transverse 

 rows; consequently the distal borders are straight and in con- 

 tact in G. globulosa, while the lateral borders are straight in 

 M. angustiloba, B. 



Erom specimens I have seen from Mount Gambier, Melicerita 

 angustiloba certainly seems to be a jointed species, and should be 

 united to Cellaria, The genera Melicerita and Escliarinella are 

 separated by d'Orbigny in consequence of the first having the cells 

 transverse, while they are quinciiDcial in the second. Latereschara 

 was also divided from Eschara on the same grounds. 



Mr. Vine has in his possession a node from this locality, which is 

 very irregular and elongate. 



13. Cauda fossilis, sp. nov. Plate XYI. figs. 51, 52. 



Cells biserial ; aperture elongate, rounded above, contracted below ; 

 upper margin recedent, with a spine on each side. Surface granu- 

 lated. An avicularium (or spine) on the inner side of each zocecium, 

 placed about one third of the length of the zocecium from the top. 

 On the side a large pore for tubular fibre, above which is a vibra- 

 culum ; on the dorsal surface cells arranged diagonally. 



This much resembles Canda arachnoides, Lamx., but differs in 

 having a smaller aperture, and in the pieces found there is no 

 median avicularium ; but possibly this may exist, as the diagnosis is 

 based on a few small fragments. In C. arachnoides the cells on the 

 dorsal surface are parallel with the median line.' 



Loc. Mount Gambier (Lond. Geol. Soc. coll.). 



14. Cabeeea etjdis, Busk?. Plate XVIII. fig. 86. 



Oaberea rudis, Busk, Cat. Mar. Polyz. p. 38, pi. xlvi. 



Zocecia elongate, oblong ; aperture elliptical, occupying about one 

 half of the front of the zocecium; area sloping inwards, very minutely 

 granular ; a spine on each side at the top of the aperture, and a small 

 opening (spinous or radicular) beyond the rim of the area; a small 

 avicularium on one side below the area. So-called operculum large, 

 entire, elliptical. Ovicel] much raised, opening arched, rather flat- 

 tened in front, with a line round the flat region. A small avicu- 

 larium on one side near the top of the ovicell. 



The fragment only consists of one row of cells ; and therefore it is 

 impossible to be quite sure of the determination ; but if not rudis, it 

 approaches very closely to it, and the vibracula apparently cor- 

 respond. 



The preservation of the operculum in so fragile a specimen was 



