EPPLECTA. 



73 



This shell is distinguished from E. layardi and E. acalles by 

 want of perforation and carination and by simpler sculpture. It 

 is also smaller. 



[I have found in one of Dr. W. T. Blanford's field note-books 

 a very good figure and a long description of the animal of this 

 species, which I give verbatim as it is so good, descriptions of this 

 sort from life being really of more value than those of the shells. 



" H. mucosa, W. Bit' . : Nilgiris. No linguiform processes to the 

 mantle. Mantle rather large. Animal dull orange, mantle yellow. 

 Tentacles blackish, with a dark line from the base of each to the 

 mantle. The lobe over the mucous pore very large. Back not 

 carinate. Toot broadly margined by a single line. Animal and 

 mantle coarsely granulate throughout and with irregular dots of a 

 darker colour on the spaces between the wrinkles and especially 

 on the edges of the foot. Animal very active." 



This description is sufficient to enable anyone to recognize the 

 species and preserve the animal for dissection. 



Blanford placed it next to E. pulchella ; but as there is con- 

 siderable doubt whether it belongs to the genus Euplecta, I 

 transfer it to the end among other doubtful species.] 



[Confining comparison to the formula of the raclula in the 

 genus Euplecta and the sinistral and dextral forms of Ariophanta, 

 marked differentiation is displayed in the far fewer teeth in the 

 raclula of the first, whereas in the last two divisions the number 

 is much greater in the proportion of 28 : 45. In the sinistral and 

 dextral species remarkable similarity is found, showing a close 

 relationship with each other and a more distant one with Euplecta, 

 differences (specific) being confined in Arioplianta more to the 

 form of the teeth themselves. To elucidate this, I have taken the 

 number of the admedian teeth, including the one or two of 

 transition form, of all the species now examined in : 



I. The sinistral Ariopliantw. 

 II. The dextral 

 III. Euplecta. 



The mean of all these formulae is interesting, showing how much 

 more numerous the teeth are that is, how much broader is the 

 central band of teeth set on quadrangular plates in Nos. I. & II. 

 than in No. III., thus : 



