EXPLANATION OF PLATES. 669 
PLATE XXIV. 
Figs. 1-6. Ampullaria cerasum, Hanl. (p. 421), Teapa: 3, young, the others full-grown specimens 
of different forms, chosen from a large number of shells from the same locality. 
re hondurasensis, Reeve, var. (p. 420), Lake of Nicaragua, specimen from Dunker’s 
collection. 
8. delatirei, Reeve (p. 419), Lake of Peten, given by Dr. Stoll to the Berlin Museum. 
2. yucatanensis, Cr. & Fisch., var. yzabalensis, n. (p. 420), Lake of Yzabal. 
10, 11. conotdea, n. (p. 423), Costa Rica, given by Van Patten to the Berlin Museum, 
two specimens of somewhat different form. 
12, 13. pealeana, Lea (p. 428), Veraguas, given by Warscewicz to the Berlin Museum, 
two specimens of somewhat different form. 
14. costaricana, n. (p. 418), Rio Saveyre. 
15. —— » young specimen, Madre de Dios. 
16. —— , another young specimen from Costa Rica, obtained by Biolley. 
17. ——- ——, Palmar. | 
PLATE XXV. 
Fig. 1. Ampullaria (Ceratodes) rotula, Mouss. (p. 425), Costa Rica, obtained by v. Seebach : 
la, 1 6, two other views of the same shell. 
2, 3. Pachychilus glaphyrus, Fisch. & Cr., var. pyramidalis, Morel, (p. 445), Panzos, very 
young specimen. . 
4. largillierti, Phil., var. nodulosus, n. (p. 451), Paso Antonio. 
5. panucula, Morel., var. tumidus, Tristr. (p. 458), Lake of Peten, Tristram’s typical 
specimen. 
6. obeliscus, Reeve, var. pyrgiscus, Fisch. & Cr. (p. 447), Lake of Peten. 
‘. lacustris, Morel., var. amphibolus, Fisch. & Cr. (p. 447), Yzabal. 
8. —— , var. major, Fisch. & Cr. (p. 448), Yzabal. 
9. —— , var. conradti, n. (p. 448), Yzabal. 
10. —— , ditto, Panzos. 
11. subnodosus, Phil. (p. 450), Costa Rica. 
12. largillierti, Phil. (p. 450), Paso Antonio. 
13. subnodosus, Phil. (p. 450), Managua. 
PLATE XXVI. 
Fig. 1. Pachychilus pluristriatus, Say (p. 449), Laguna de Chapala. 
2. largillierti, Phil. (p. 450), Mirandilla. 
3. , var. salvini, Tristr. (p. 451), Rio de la Pasion, one of Tristram’s typical 
specimens. | 
4: dalli, Pilsbry (p. 456), Tehuantepec, copied from Pilsbry’s figure [Proc. Acad. Phil. 
1896, p. 269], to show the peculiar form of the outer lip. 
5-9 largillierti, Phil., var. stoli, n. (p. 452), Retalhuleu, specimens of different forms 
from the same locality. 
10-20 turatii, Villa (p. 454), Atoyac, specimens of different forms chosen from a large 
number of shells from the same locality: 10 and 11, young; 13, 15, and 16, probably 
not quite full-grown; 18, 19, and 20, very old. 
