478 PROCEEDINGS OF THE ACADEMY OF 



plica, followed by a straight lunella, or a short, low callous nodule 

 representing the lunella. There is no lower palatal plica, nor 

 inward curve of the lower end of the lunella, representing such 

 plica. 



Since the lunella is a secondary evolution-product, formed by 

 the coalescence of primitive palatal plicse, it is natural that species 

 representing certain intermediate stages should occur. 



Clausilia micropeas Mlldff. PI. XXVIII, figs. 41, 42, 43. 



Von Mollendorff, Journ. Asiatic Soc. Beng., LI, Pt. 2, No. 1, p. 12 ; 

 LIV, Pt. 2, No. 1, p. 64. 



A specimen from Hungerford's collection, doubtless one of the 

 original lot, was kindly lent me by Mr. E. R. Sykes. On account 

 of its relationship with the following species, figures and descrip- 

 tive notes are here given. It has not before been figured. 



The pale buff, slender shell is attenuated above, and consists of 

 nearly 9, moderately convex whorls. It is delicately costulate- 

 striate. The aperture is piriform- ovate, with moderately reflexed 

 lip, which is quite deeply eraarginate above. The superior lamella 

 is vertical, rather slender and high, marginal, and continuous with 

 the spiral lamella. The inferior lamella is deeply receding, not 

 visible from in front. Within it ascends straightly. The sub- 

 columellar lamella is wholly immersed. Within, the spiral and 

 inferior lamellae are of equal length, ascending to a point on the 

 ventral side just above the superior lamella. The principal plica 

 is rather short, not quite a half -whorl long, its lower end visible 

 deep within the throat, whence it extends almost past a strictly 

 lateral position. Below it there is a rather long upper palatal 

 plica, and then a very low, rather wide and straight lunella. No 

 lower palatal plica. 



The long, narrow clausilium (PI. XXVIII, figs. 44-46) is 

 parallel-sided, slightly acuminate below, and not emarginate pos- 

 teriorly. 



Length 10.5, diam. 2 mm. 



In this specimen the lunella is apparently better developed than 

 in that opened by Dr. von Mollendorff, who in his first description 

 states that there is a short upper palatal plica and sometimes a 

 second punctiform one, the latter evidently being the vestige of a 

 lunella. In his second article he finds " that there is an indica- 

 tion of a lunella below the second (generally punctiform) palatal 



