BY G. I. PLAYFAIR. 195 



Long. 33; lat. 27/^. 



Auburn. 



A few somewhat similar are Cos. hivertex Rac, Desm. Nowe, 

 T. 1, f.20; Cos. isthmocliondrum var. hrasiliense Borge, Desm. 

 Regnell. T.2, f.21; G. limnopldlum Schm., Alp. Alg. T.15, f.20. 

 The nearest approach is C. Pilgeri Schm., Aus. Braz. T.4, £.13. 

 which curiously enough is exactly the same size. It has, how- 

 ever, five strongly marked granules on each side; and Schmidle 

 expressly says " seen from above elliptical and not tumid." The 

 above has three rows of almost invisible minute granules across 

 the edges, just sutticient to cause three slight denticulations on 

 the margin. 'J'he two large granules are conspicuous in end view. 



Cos. JKNISE.TENSE Boldt. /ij AUSTRALE, n.var. (T.v. f.l4). 



Forma dorso depressa fere plana; angulis inferioribus obtusis 

 fere rectis; lateribus verticalibus leniter convexis; angulis superi- 

 oribus late rotundatis; puncta-granulis in series et verticales 

 circ. 10 (granulis circ 7) et oblique trans versales ordinatis, ornata; 

 in centro tumore humili granulis 9 majoribus in series 3 verticales 

 ordinatis, instructa. A vertice visa elliptica utrinque in medio 

 tumore parvo 3-granulato praedita, apicibus late rotundatis. 



Long. 35; lat. 26-29; crass. 18/x 



Murray's Lagoon, Collector. 



Cf. Boldt., Siber Chlor. T.5, f.l3. 



Cos. ORTHOPUNCTULATUM Schui., Alp. Alg. T.15, f.l5. 

 (T.v. f.27-28). 

 Forma semicellulis a f route visis perfecte ellipticis. 

 Long. 30-34; lat. 34; crass. 15-17: zygo. s. ac. 15; c. ac. 30/a. 

 Coogee. 



Cos. MuRRAYi, n.sp. (T.v. f..l9). 



Cos. parvum, suboblongum, clepsydraforme, paullo longius 

 quam latum, medio sinu breve lineato constrictum. Semicellulae 

 subpyriformes, ad apices versus inflatae; dorso lato truncato 

 paullulo producto; lateribus e basi angusto divergentibus, sursum 

 convexis. A vertice visae regulariter ovales, apicibus late 

 rotundatis. Membrana achroa glabra. 



