1871.] F. Stoliczka— Notes on Terrestrial Mollusca. 219 



marked with stronger strioc of growth. The measurements of the 

 largest specimen of this variety are: larger diam. 1 3*6, small 

 diam. 12*2, height 9*5 mm. 



When fresh, the shell of \_Durgella~] honesta is always horny and 

 translucent, the whorls at the sutures adpressed, the surface 

 smooth and polished, except on the last whorl where, near the 

 suture and round the umbilicus, a fine spiral striation is usually 

 observable. The aperture is always oblique, with the upper, or 

 sutural, margin of the outer lip considerably more produced, than 

 the lower or umbilical margin ; the inner lip is very thin and the 

 colurnellar lip at the base distinctly reflected and somewhat 

 thickened, so as almost entirely to cover the umbilicus. 



Full grown shells are comparatively solid, especially those occur- 

 ring on limestone ground, but the young are generally of very thin 

 texture and their aperture also has not the oblique form of the old 

 shell. This makes the former very closely to resemble young speci- 

 mens of Macrocli. vesicida or lect/ this, as has already been noticed. 



The animal of the Moulmein variety is narrow, very long,, pale 

 white, pedicles and the terminations of the tentacles leaden grey, 

 as well as the upper part of the foot posteriorly ; the tail gland 

 is superseded by a very distinct hook ; the mantle lobes are well 

 developed, both the upper portions being reflected over the shell. 

 By some accident, however, my spirit specimens were lost and I 

 am, therefore, unable at present to give sufficient details regarding 

 the anatomy of this species. Semper (Keisen im Arch, der Phil,, 

 vol. iii, pt. I, 1870, p. 18,) gives some anatomical details of a 

 dried up sx^ecimen received through Dr. Anderson, but not, as is 

 stated, from the Andamans. Dr. Anderson had collected his 

 specimens in Upper Burma, when with the Yunan expedition, and 

 some of these specimens he forwarded to Dr. Semper ; the species 

 does not occur on the Andaman islands. 



I have also examined some of these dried Burmese specimens, 

 and I find the animals agree in external characters exactly with 

 the Moulmein ones. The tail gland is superseded by a very distinct 

 hook ; the centre portion of the sole is narrower than the outer 

 portions. The left shell lobe has two linguate appendages, one 

 extending over the peripherical portion of the shell, the other, a 



32 



