SUCCINEA.: 339. 
One of the specimens from Antigua is of about the same size as Morelet’s type; the. 
two others are remarkably smaller, length 8 (instead of 11), diameter 4 (instead of 5), 
and the length of the aperture 5 (in Fischer and Crosse’s figure? 64) millim. The 
aperture in all three is placed very obliquely, and in consequence occupies only about 
5 of the whole length of the shell, although the length of the aperture, measured in 
its plane, obliquely to the axis of the whorls, is to the whole length of the shell as 5:8 
or 53:93. The tip in none of them is of darker colour than the rest of the shell. 
4. Succinea undulata. (Tab. XIX. fig. 10.) 
Succinea undulata, Say, New Harmony Disseminator of Useful Knowledge, ii. p. 230 (1829) '; 
Binney, Complete Writings of Say, p. 387; Pfr. Monogr. Helic. Vivent. ii. p. 526°; 
in Martini & Chemnitz, Syst. Conch.-Cab., ed. 2, Daudebardia, Simpulopsis, Vitrina, and 
Succinea, p. 50, t. 5. figg. 12-14 (1854)‘; Binney, Proc. Acad. Phil. 1860, p. 151°; 
? Fisch. & Crosse, Miss. Scient. Mex., Mollusca, i. p. 656, t. 27. figg. 4, 4a, d°. 
Succinea petiti, Beck, Ind. Moll. p. 98 (1837) (sine descr.)’. 
Succinea obliqua (Say), v. Mart. in Malak. Blitt. xii. p. 50 (1865) °. 
Hab. Centrat Mexico: Mexico, without nearer indication of locality, probably near the 
capital (Say!~°; Beck’; Uhde’; ? Fischer & Crosse ®); Ivapuato, in the State of 
Guanajuato, near the Rio Lerma, in the open country, and Sayula, State of Jalisco 
(Hoge). 
S.E. Mexico: Santecomapan, near Tuxtla, State of Vera Cruz (Sallé°). 
This is the largest of the Mexican species of Succinea. A specimen collected by 
Uhde measures: long. 19, diam. 11; apert. long. 154, lat. 8 millim.; aperture 
occupying +3 of the whole length. One obtained by Hége at Irapuato has a diameter 
of 11 millim.; aperture 14 long and 8 broad, but the apex is injured. It is allied to 
S. obliqua, Say, but distinguished from it by the more wrinkled surface, especially 
of the last whorl, and by the less convex upper whorls, with shallower sutures. 
S. obliqua does not extend, according to Binney, further southward than Georgia and 
Arkansas. 
Say’s type specimen of S. undulata is lost, and A. Gould has suggested that it may 
have belonged to S. Juteola ; but the words in Say’s description “ testa subovata, pallide 
flavescens, translucens, fragilis, obsolete rugosa,” and chiefly ‘‘ anfractus ultimus corru- 
gatus,” agree much better, I think, with the shell which Dr. Pfeiffer has figured as 
S. undulata than with S. luteola. Moreover, the peculiar coloration of S. luteola is 
not alluded to in Say’s description, and its characteristic shape, with remarkably small 
aperture, does not suggest any affinity with S. ovalis, urged by Say himself. Concerning 
Fischer and Crosse’s figure ®, I do not see in it the scattered stronger wrinkle-like striz 
which are distinctly visible in Pfeiffer’s figure*. As regards S. petitt, Beck, the late 
Dr. Mérch has informed me that the type specimen in the Copenhagen Museum 
is 15 millim. long, and not unlike a somewhat lengthened specimen of Limnea 
