89 



much smaller than the type, but the characters, on which the species 

 was proposed, appear to be constant. 



A variety of Lucidella aureola is so strongly sculptured with gran- 

 ules, that it will be conveuient to designate the variety with the name 

 of granulosa. 



A large and very dark colored variety of Cyclostoma Jayanum has 

 the outer peritreme black, and may be designated by the name of 

 nigrilabre. 



Having received fresh specimens, with their opercula, of Cyclos- 

 toma Chittyi, I am able to confirm the validity of the species, 

 which was proposed with some hesitation on p. 1. of this work. The 

 whorls of these shells have a little more diameter than those of the 

 original specimen, being about equal to those of C. Jimbriatulum 

 Sowb. In addition to the peculiarities of our species before mentioned, 

 we find those of the operculum especially worthy of notice. In C. 

 fimbriatulum, the spiral lamella is inclined almost to a horizontal po- 

 sition, with a breadth equal to one-fourth the diameter of the opecu- 

 lum. In the operculum of C. Chittyi, the spiral lamella, in its last 

 whorl, is half as wide as the operculum, and is nearly perpendicular, 

 with the upper edge strongly reflected. It has very strong oblique 

 stria3, which are continued^over the reflected summit. In C Chittyi, the 

 peritreme of the aperture is considerably produced : the intercarinal 

 spaces are colored more or less deeply w^ith brown, like C. amandum. 

 It is one of the most elegant species in the beautiful subgenus Choa- 

 nopoma. 



The two species, which were referred to Cylindrella, as a Geome- 

 laniform group, are Geomelaniae, in which the linguiform part of the 

 labrum is obtuse and moderately produced. "We may now reckon 19 

 species of this interesting genus. In Geomelania Bicardsleana 

 Mr Chitty has obsei'ved an operculum. The other species referred 

 to will take the name of Geomelania pygmaea. 



In the description of Geomelaniae on p. 18, the mean divergence 

 was not correctly estimated, in consequence of the erroneous assump- 

 tion that the divergence of the lost whorls was greater than that of 

 the remaining whorls. 2*^ or 3° should be deducted from the amount 

 assigned to each species. " 



Erata. In printing the description of G. ekfjans, the word ' except' was omit- 

 ted from the last sentence, which should be read precisely as in the description of 

 G. striosa on a subseqcnt page. 



On p. 47, line 17 from the botlom, erase ' H. haemastoma Moric,' and three 

 lines below for ' two' read one, and for ' third' read ' second. 



On p. 51, 2nd line from the bottom, for ' haeiiiastoma Moric. read ' H- aurantia 

 Gray.' 



