LEPRALIA CANTHAllIFORMIS. 299 



Thompson) : the Minch ; Shetland^ common, between 

 tide-marks (A. M. N.) ; Orkney (C. W. P.). 



Geographical Distribution. Rhode Island and New 

 Jersey (Leidy) : Baliusia and Southern Norway, the most 

 common littoral species (Smitt) : France, S.W.j 6-10 

 fathoms (Fischer) : Roscoff (Joliet) : Adriatic, on shells, 

 stones, and Algse, pretty common (Heller) : 7-10 fathoms, 

 island of Lussin, Adriatic (Grube) : Mediterranean 

 (Lamx.) . 



Range in Time. Coralline Crag (S. Wood). 



This handsome species is for the most part a littoral 

 form, and is extremely abundant between tide-marks on 

 many parts of our coast. The smaller pebbles are often 

 completely incrusted by it. 



In young cells the front wall is thin and silvery, and 

 covered with simple circular punctures ; but with age a 

 thick glassy crust forms over the primitive lamina. In 

 this state the ridges between the foramina frequently rise 

 into prominent nodules. 



According to Smitt, L. Pallasiana occasionally assumes 

 the Hemescharine habit, and forms free and erect ex- 

 pansions. 



Lepralia canthariformis. Busk, 



Plate XXXIII. fig, 4. 



Lepralia canthariformis, BusJc, Quart. Journ. Micr. Sc. viii. (186U), 143, 



pi. xxvi. figs. 3, 4. 

 Lepraua Pallasiaxa, Tar., Norman, Shetland Pol., Kep. Brit. Assoc, for 



1868, 307, 308. 



'^'■Zo£e<:ia broadly ovoid, surface granular, punctate, shining; 

 orifice large, suborbicular, oblong or irregular ; peri- 



