602 It. J. HARVEY GIBSON ON THE 



expresses a hope that the anatomy and development of this form may be taken 

 up by some one ; and although it is to be regretted that the task had not fallen 

 into more competent hands than the present writer's, yet he hopes that he has, 

 in the following research, done something towards dispelling the prevailing 

 uncertainty in regard to many questions, which have too long demanded inves- 

 tigation. The desideratum at present in the natural history, more especially of 

 the Mollusca, is a series of complete accounts of all the more common types ; 

 and it seems to the author that much more might be made with regard to 

 interesting problems of Phylogeny, if, instead of elaborating a number of small 

 detached papers on special points, some naturalists were, for a few years at 

 least, to devote themselves to the working out of complete monographs of the 

 most important forms belonging to each group. 



A considerable amount of work has been done in the way of naming and 

 identifying the numerous species of the Patellidce ; although, owing to their 

 identification being based on unimportant external features, e.g., the form and 

 colour of the shell and exposed parts, many forms have received several 

 synonyms, and have consequently been described several times. 



In this summary of research, the author desires rather to indicate the 

 leading papers on which our knowledge of Patella is based, than to give any 

 detailed account of these papers themselves, which he prefers to postpone until 

 the different organs with which they deal come to be discussed. 



The limpet is mentioned first, of course, by the all-observant Aristotle, 

 who gives a brief account of some of its more obvious characters and habits, — 

 referring especially to its moving from place to place and returning after each 

 forage to its old roosting place. General descriptions have been given by 

 Linnaeus, Born, Adanson, and various other naturalists of the last century; 

 and we are generally able to identify the species described by them with those 

 now inhabiting our coasts. Similar accounts are given by later conchologists, 

 more especially by Keeve, Hanley, Gwyn Jeffreys, Gray, and Woodward. 



The first attempt at giving a complete account of the anatomy of Patella is 

 that of Cuvier in his Memoires, where the species is described with tolerable 

 fulness. Gray, and later Dall, have described and figured the radula, the 

 mechanism of which has been lately fully investigated by Geddes. The renal 

 organs have come in for a good deal of attention from Lankester, Dall, and 

 Cunningham, and are perhaps the most thoroughly investigated portions of the 

 whole animal. The respiratory organs have not been so fortunate, having been 

 examined, in allied forms only, by Williams (whose paper the writer has not 

 been able to see). Some remarks on the respiratory organs by Blainville and 

 Adanson are mainly contradictory of each other. The nervous system has been 

 investigated by Brandt and by Spengel ; and their admirable work leaves little 

 to be done in that system, save to make a few remarks on histology. Spengel 





