XX INTRODUCTION. 



Specimens of many exotic species have been brought 

 to me ; but these I have considered it prudent to sup- 

 press. One species, however, is deserving of notice, 

 although it has come too late for insertion. It is the 

 beautiful Spirula australis, of which fourteen specimens 

 were gathered by myself on the sands to the north of 

 Don-mouth, on the 4th and 6th of March, 1843, but 

 of which the first example was found by one of my 

 pupils, Mr. William Robertson, and the second by Mr. 

 Leslie. 



Several species supposed to be new to science are de- 

 scribed. Respecting these it is proper to apprise the 

 student, that, although apparently not mentioned in any 

 of the works to which I have access, some of them 

 have probably been already noticed. They amount to 

 about thirty, and are named as follows: — Polysto- 

 mella Gulielminse, P. crenulata, P. nautilina ; Discorbis 

 pulchellus ; Vermiculum disciforme, V. planatum ; Tex- 

 tularia oblonga, T. obtusa ; Dentalina Davidsonii ; La- 

 genula reticulata ; Natica rutila, N. squalida ; Rissoa 

 gracilis ; Odostomia scalaris, 0. plicatula, 0. Marionse, 

 0. Annse, 0. oblonga; Tornatella pellucida, T. oblonga; 

 Fusus Buchanensis ; Bullsea catenulifera ; Halia Fle- 

 mingiana ; iEolis Murrayana, M. Lesleiana ; Sphseros- 

 toma Jamesonii ; Pecten Isabellse ; Cyclas flavescens ; 

 Pisidium Joannis ; Ascidia opalina; Tritonia atrofusca. 



