BLANFORD: LAND AND FRESH-WATER MOLLUSCA FROM SIAM. 277 
diameters and 6 mm. in height, whereas the typical form from Tavoy 
measured 17, 16, and 9mm, The colour of the Siamese shell, too, 
is ight yellowish fulvous, not whitish horny, and the spire is rather 
lower than in the typical Tenasserim form. 
The anatomy of Jf. anceps was described by Stoliczka (Journ. 
Asiat. Soc. Bengal, 1871, pt. ii, p.. 233, pl. xvu, figs. 1-3), who 
referred the species to the genus Lotula of Albers. Godwin-Austen 
(Proc. Malac. Soce., vol. iii, p. 174) has shown that this form must be 
included in Macrochlamys, despite its being sharply carinate. 
7. Hemipiecta pistrnota, Pfr. 
Helix distincta, Pfr.: Zeitschr. Malak., 1850, p. 69; Mart. & Chemn., 
2nd ed., Helix, No. 853, pl. exxxiv, figs. 1, 2 (1852); 
Morlet, [Arvophanta (Hemiplecta) |, Journ. de Conch., 1891, 
p. 281. 
Helix Neptunus, Pfr.: Proc. Zool. Soc., 1861, p. 190; id., Novit. 
Conch., p. 176, pl. xlviu, figs. 1, 2. 
Helix Pluto, Pfr.: Proc. Zool. Soc., 1862, p. 268; id., Novit. Conch., 
p. 210, pl. lv, figs. 8, 9. 
Helix pernobilis, Fér.: apud Pir., Novit. Conch., p. 177, pl. xlviu, 
figs. 3 & 4, nec Fér. 
Hemiplecta Neptuna, G-A.: Proce. Malae. Soc., vol. iv, p. 33. 
I have compared the shells sent by Mr. Daly with the types of 
HH, distincta from Cuming’s collection in the Natural History Museum. 
Mr. Smith, to whom I am indebted for calling my attention to these 
and to the types of H. Neptunus, assures me that there is no doubt 
they are the original specimens in both cases. Owing to the fact 
that H. distincta, when originally described, was said to be from the 
Moluccas, there has been much confusion as to its identification, and 
it is, I think, owing to this that Colonel Godwin-Austen has referred 
Mr. Daly’s shells to 7. Neptunus, and has regarded this and /. distincta 
as different species. One of the shells sent by Mr. Daly is scarcely 
distinguishable from one of the types of H. distincta. Another 
specimen from Mr. Daly agrees better with H. Weptunus, whilst 
a third approaches H. Pluto, and I regard all as varieties of the same 
species. The shell identified by Pfeiffer as H. pernobilis must, 
I think, be another variety, but the original H. pernobilis of Férussae 
(only known from his figure) may be quite distinct, the reversed 
basal margin of the peristome, the external coloration, and the 
banding inside the mouth as represented in the figure being very 
ditferent from the Siamese form. 
The locality of the Molucca Islands, originally quoted by Pfeiffer 
for H. distincta when the shell was first described in 1850, appears 
to have been corrected by Haines (Ann. Lyc. New York, vi, 1856, 
p. 158). The locality was evidently regarded as erroneous by Pfeiffer, 
for it is not mentioned in the later supplements to his Mon. Helic. Viv. 
The figure in Martini & Chemnitz is not good, and appears not to 
have been taken from any of the types in the Cuming Collection. 
There is evidently also much confusion as to the forms dissected by 
Semper. 
