LITTOEINID^E. 335 



I have been wishing for an apt opportunity to issue my paper, 

 which only occurred in the April Number of the ' British 

 Mollusca/ wherein malacologists will observe that Professor 

 Forbes, with singular coincidence, by his views, corroborates 

 mine, written many months ago, from actual examination of 

 the animals. Though the learned Professor has admitted into 

 his work varieties that have not the slightest pretensions to be 

 styled species, for the sake of exciting further investigation of 

 them, yet in page 52 of his summary of the Littorina, he 

 boldly and emphatically repudiates all paternity with the 

 pseudo-species. He says 



" In the preceding account of the Littorince several are 

 described as species which many of our ablest naturalists 

 regard as varieties, whilst others are considered as varieties 

 which some hold to be worthy of specific rank ; our conviction 

 is, that the result of a completed knowledge of this genus 

 would be a reduction in the number of true British species. 

 Taking the most permanent features of the animal and its 

 shell as our guide, we are inclined to reduce the true spe- 

 cific types to L. neritoides, L. littorea, L. littoralis and 

 L. rudis." 



My views being thus supported, I send forth without hesita- 

 tion these observations made long ago, and I feel gratified 

 that my investigations of this tribe have received the corrobo- 

 ration enunciated by that eminent Professor. 



Before I give the descriptions of the types of the genera of 

 the LittorinidfBj I will make some remarks on the prevalent 

 practice of naturalists to create species from mere varieties : 

 this anxiety can only be attributed to their wish to extend 

 our knowledge of new and interesting objects. That these 

 views are desirable and laudable cannot be questioned, but it 

 is to be feared that the zeal of these gentlemen, combined 

 with the ardour of rivalry in the race with their brethren in 

 the same pursuits, have been the cause of a departure from 

 those principles and laws which are considered indispensable 

 to arrive at just conclusions in the establishment of genera 

 and species ; or in other words, in laying down the true bases 

 of the differential features of the families, genera and species 



