APPENDIX. 525 



clavate or hammer-like appearance, becoming thick, angular, 

 bevelled to a sudden edge, straight in front, without auricles 

 or central indentation. The tentacula are very short, and 

 their tips less marked and folded than in many others of this 

 tribe. 



CHEMNITZIA CLAVULA. (P. 436.) 



Exmouth, July 1854. 



After a Japse of two years, a single, beautiful, lively specimen 

 of this rare species has been met with, which enables me to 

 say'that the original notes are correct ; I can only add a few 

 minor particulars, which might have been neglected, had I 

 not wished to give naturalists the means of verifying decisively 

 this elegant and very scarce creature. 



The tentacula are extraordinarily short and broad, in con- 

 sequence of the auricular portions that spring from their 

 external margins unfolding and forming a large, fine, arcuated 

 membranous leaf, that terminates just under the apical in- 

 flations. 



The foot on the march, when the animal is agitated, can be 

 pushed into longish auricles, and in consequence shows a con- 

 siderable curved hollow in front ; this fact is common to all 

 the Chemnitzia, but in deliberate progression it becomes trun- 

 cate with subdued angular points ; the posterior extremity in 

 the example observed was slightly emarginate on the right 

 and left sides, giving the central portion the aspect of a 

 rounded or blunt stylet. On each side of the foot, when the 

 animal is in motion, there is a marginal series of about ten 

 very minute glossy points. 



This beautiful creature was remarkably free, and allowed 

 me to see the fine line of the proboscidal fissure on the ros- 

 trum immediately below the eyes. It was taken in the same 

 habitat as the original examples. 



I have omitted to state above that the foot is constricted 

 gradually below the auricles ; it is not narrow, and can, on the 

 full march, be extended to the second basal volution : when 

 that happens, its posteal emarginations nearly vanish. 



The apical reflexion of the shell is less pronounced than 



