1890.] THE YOUNG NATURALIST. 125 



Patella has a habit of "licking" the rocks in a most audible 

 manner, and the animal is likewise undoubtedly responsible for the 

 formation of the innumerable rings sunk in the stone in all directions, 

 caused by the abrading action of the sharp margins of the shells. 

 This rather points to the fact that the molluscs have fixed places of 

 abode, only leaving them when searching for food, returning when their 

 appetite is satisfied. A sharp and sudden blow will dislodge a speci- 

 men instantly, but to get them off in any other way will prove an 

 hallucination of an aggravating type. 



(to be continued). 



THE PTEROPHORINA OF BRITAIN, 

 By J. W. Tutt, F.E.S. 

 Continued from page 84, Vol. XI. 



P. gonodactyla, Schiff. — This double brooded species is especially 

 interesting : — (1). It offers a great deal of colour variation which is in- 

 timately connected with the seasonal variations it also exhibits. 

 (2). The two broods offer very remarkable differences in their man- 

 ner of feeding, the early (April and May) broods feeding inside the 

 capitula of Tussilago far/am, the second brood mining, when young, 

 under the fluffy epidermal covering of the petioles and leaves, and 

 afterwards living more exposed. (3). The species spins a cocoon in 

 which it changes to a characteristic "plume" pupa. Nothing was 

 known of the life-history of the second brood, until I bred a large num- 

 ber of specimens from ova in September 1888, vide " Entomologist's 

 Monthly Magazine," Vol. XXV., pp. 104-105, but most of the details 

 of this brood are now well known. 



Synonymy : — Gonodactyla, Schiff., Sys. Verz., 320 ; Zell. ' Isis ' 

 (1841), 777. Tesseradactyla, Treit. IX., 2,230 ; Dup. XL, 313, 5, 

 IV., 88, 8. Tfigonodactylus. Stn. Cat. 31; Stn. 'Manual' p. 440; 

 ' Zoologist ' (1858), 3064 ; Haw. 478. 



This species has offered a considerable amount of difficulty relative 

 to its synonymy. It is the tfigonodactylus of most of our British lists, 

 but there is little doubt that gonodactyla is the prior name. Mr. C. G. 

 Barrett "Entomologist's Monthly Magazine," Vol. XVIIL, p. 177, 

 writing of this says : — " For Platyptilia trigonodactylus, Haw., the prior 



