Foraminifera and Ostracoda. 195 



and in this, as in other features, such as the broad curvature of 

 the septa, it closely approaches the vaginuline style of test. The 

 longitudinal costae are fairly well developed, but are somewhat 

 interrupted near the sutural depressions. Length of specimen 

 0.4 mm. ; greatest width 0.3 mm. 



Ocmrrence. — One specimen; Jurassic, Greenough River district. 

 West Australia. [2137]. 



Cristellaria costata, F. and M. sp., var. seminuda, nov. 

 (PI. XXII., Fig. 15). 



Ronarks. — This variety differs from the type in the interrup- 

 tion of the longitudinal costae on the central area of each 

 chamber. The test is also more elongate, with fewer chambers, 

 and is less inrolled than the type-form. The peripheral mai'gin 

 is bordered by a narrow keel. 



Length of test, 0.38 mm.; width, 0.22 mm. 



Occurrence. — One specimen; Jurassic, Greenough River district, 

 West Australia. [2138.] 



Cristellapia cf. limata, Schwager. (PI. XXIL, Fig. 16). 



Cristellaria limata., Schwager, 1868. Benecke's Geog. Pal. 

 Beitrage, vol. i., p. 657, pi. xxxiv. 



C. limaia, Schwager, Wisniowski, 1890, Pamietnik wydz 

 matem. — przyrodn. Akad. Umiejetn. w. Krakowie, vol. xvii., p. 

 34, pi. ix. (ii.), fig. 19. 



Remarks. — The group of 0. crepidula, Fichtel and Moll, sp., 

 comprises many varieties or so-called species, but out of all the 

 well-known examples figured none can be quoted as exactly 

 matching the West Australian specimens. The nearest allied 

 form is that figured by Schwager from the Ammonites (Sonninia) 

 sowerbyi zone (middle brown jura, lower oolite) of Germany; 

 and by Wisniowski from the Ammonites (Cosmoceras) ornatus 

 zone (Middle Oolite) of Poland. The well-rounded outline of the 

 back of the test seen in our specimens is also exemplified in C. 

 limata, but the latter form is not so strongly compressed on the 

 sides. Another form which may be noticed is C. opercula, Crick 

 and Sherborn, from the upper lias of Moulton, Northampton, 



