GENERA AND SPECIES. I2Q 



Nezera. (POROMYID^E.) Plate xv. 



180. abbrcviata, in. x in, hinge line obtusely angular, shell nearly 



transparent. 



181. costellata, gin. x ^ in. hinge line straight, hinge plate narrow and 



slight, left valve with a small cardinal tooth. 



182. rostrata, ^ in. x /^ in. hinge line straight, hinge plate moderately 



broad, no cardinal tooth. 



183. cuspidata, in. x T ? in. hinge line obtusely angular, shell opaque 



and noticeably inequivalve. 



Neritina. (NERITID&.} Plate xxii. 



356. fluviatilis, i Q - whorls 3, the last exceeding two-thirds of 



the shell. 



Nucula. (NUCULID^E.) Plate i. 



Inner margin notched 



1. sulcata, f in. x in. beaks not terminal, teeth 10 to 12 on 



anterior side, and 20 to 24 on posterior side. 



2. nucleus, ^ in. x in. beaks terminal, teeth 15 on anterior side, 



and 25 on posterior side. 



3. nitida, ^ in. x J in. Shell shining, teeth 12 on anterior side, 



and 20 on posterior side, beaks prominent. 



Inner margin not notched 



4. tennis, % in. x ^ in. beaks thin, teeth 6 on anterior side, and 



1 6 on posterior side. 



Of 2 there is a variety, radiata, which is larger, flatter, and has radiating streaks 

 of purple. 



Odostomia. (PYRAMIDELLIDM.} Plate xxvi. 



Pillar straight, shell smooth 



502. nitidissima, ^ in. whorls 7, suture wide and deep. 



501. acicula, in. whorls 8 or 9, not angulated, suture narrow. 



500. scilla, in. whorls n to 12, angulated, suture narrow. 



Pillar straight- 

 Shell ribbed or reticulated 

 Whorls more than 10 



497. vufa, in. whorls 10 to 13, colour drab, often blended 



with brown. 



498. lactea, % in. whorls 12, colour white, ribs curved and 



oblique. 



499. pusilla, in. whorls 12, colour white, ribs curved, but 



not oblique. 



