MOLLUSOA., 645 
AMNICOLA (p. 430). 
4(a). Amnicola (?) vulcani, sp.n. (Tab. XLIV. fig. 13.) 
ga, 9 a, 9 2? ? Pp 
ovata, 2 longitudini : ; i i 
. a Aes 8 nis teste sequante, margine externo tenui, columellari arcuato, crassiusculo. 
ong. 5, diam. 23, apert. long. 2 millim. 
Hab. W. Guatemata: Lake of Atitlan (Bernoulli, 1869: given by Dr. O. Stoll). 
It may be added that the locality for this species, the Lake of Atitlan, is bordered on 
the south side by three volcanoes, and has no drainage to the Pacific. 
4(s). Amnicola stolli, sp.n. (Tab. XLIV. fig. 14.) 
Testa conoidea, ventricosa, perforata, nitidula, pallide fusca ; anfr. 4, valde convexis, sutura profunda; apertura 
: 4 . e - « . e hd hd 
eles § longitudinis teste occupante, margine externo tenui, columellari subincrassato, modice arcuato. 
Long. 3, diam. 2, apert. long. 14 millim. 
Hab. W. Guarema.a: in wells of the town of Antigua (Stol/). 
Amnicola palomaensis (p. 424). 
Bythinella palomaensis, Dall, Proc. U.S. Nat. Mus. xix. p. 369, t. 31. fig. 9 (1896) *. 
Amunicola costaricensis (p. 435). 
To the localities given, add :— 
Hab. FE. Costa Rica: small streams between Madre de Dios and Rio Hondo, 80 metres 
(Pittier). 
[Crntrat Costa Rica:| Cartago (S¢éoll). 
PACHYCHILUS (p. 487). 
Pachychilus glaphyrus (p. 438). 
h. Var. pyramidalis (p. 445). 
To the localities given, add :— 
Hab. Centra, Nicaraaua: Lake of Managua (Rothschuh, in Mus. Berol.). 
j. Var. bicarinatus. 
Pachychilus glaphyrus, var., Pilsbry, Proc. Acad. Phil. 1892, p. 389, t. 14. fig. 6°”. 
Two interrupted keels on the last two whorls, the upper one in the sutural line, three in the preceding whorls ; 
vertical plaits vanishing already in the upper whorls; base of the last smooth. 
Long. 75, diam. 20, apert. long. 16 millim. 
Hab. 8.E. Mexico: State of Tabasco (Rovirosa *"). 
This form agrees with the var. potamarchus in the want of spiral ridges at the base 
of the last whorl, and seems to indicate a peculiar series recognizable by the above 
mentioned characters, both varieties being known only from Tabasco. 
Pachychilus largillierti (p. 450). (Tab. XLIV. fig. 17.) : 
I give here the figure of a living specimen from the Lake of Amatitlan, drawn by 
Dr. O. Stoll. 
