393 Mr. W. Clark on the Chenmitzise. 



tioned the C. unica aad C nitidissima, which I think are un- 

 doubted Chemiiitzice, as far as conchological indices enable me to 

 judge ; and we shall not be surprised if the Aclis ascaris proves 

 a CJmmniizia. Uriii la^ih^ro Jfirlt h^ y-('.'o;);<it> '•(<' ;- 



The beautiful Chemnitzia Gvlsomei^ our own discovery more 

 than thirty years ago : I have not a character to add or detract 

 from my late description, except that after the phrase of the 

 specific character, " peripheria iutegra/' interdum intcrnipta may 

 be added, as my specimens differ. The apex is subreiiexed — 

 indeed every character denotes the Chenmitzian animal ; there is 

 not a single point of the Rissoa in it. 



With respect to the so-called O, turrita of authors, much dis- 

 cussion and difierence of opinion have lately existed to determine 

 if it is a distinct species, or a variety of an established one. It 

 is inferred from the specimens being more or less spirally striated 

 throughout, that it is a good species. My own opinion has 

 changed more than once : at one time I thought it might be an 

 aberrant variety of Chem.insculpta ; in this I am mistaken : again, 

 I had made up my mind that it could not belong to Chem. acuta ; 

 in this point I am also mistaken, as it turns out to be scarcely a 

 variety of that common species ; it is one of the individuals with 

 the more inflated volutions. I have forty specimens, which I 

 took the trouble separately to submit to the microscope, and in 

 those which were not worn, I was agreeably surprised to receive 

 the solution of this problem, by finding that every recent shell 

 was finely spirally sti'iated throughout ; in some the striae were 

 more apparent, and easily seen by a Coddington lens ; in other's 

 the microscope was required, and with ordinary powers, even in 

 the most apparently glabrous shells, the spiral lines became con- 

 spicuous. In the shells that have not been much rubbed, the 

 strife have acquired a crassitude by exposure to the air, as is 

 always the ease, which renders them more visible ; I have such ; 

 but in the perfect recent ones they are excessively fine, and can- 

 not be detected without considerable optical assistance. This is 

 the simple history of the so-called C. twrita, which certainly is 

 nothing more than the Chem. acuta, with the striae somewhat 

 more apparent than usual ; such are in our cabinet, and mala- 

 cologists will find that they have not a perfect recent specimen 

 of the C. flCM^a which is not more or less spirally striated through- 

 out. This question may be considered finally settled; it admits 

 of no further discussion. I have had the advantage of viewing 

 Mr. Barkers typical tablets of this variety of the Chem. acuta. 



The " dolioliformis," nonnuU., has, I think, sufficiently been 

 shown to be the Chemnitzia Sandvicemis of Mr. Walker. We 

 need only say of the C. insculpta, C. plicata and C unidentata, 

 that they are old Montaguan sjiecics ; the two latter animals are 

 described by us. The C. conoidea is a well-marked coralline zone 



