MUREX. ROCK-SHELL. 87 



lar polished, with a keel-like ridge along the canal, and 

 rugged on the outside : length six inches 5 breadth, inclu- 

 ding the protuberances, four inches. 



We had frequently heard it remarked, that the fisher- 

 men of the northern coasts of Ireland occasionally saw, 

 what they called the great rock-shell, in calm weather, and 

 deep in the water. Our attention was naturally awakened 

 by this relation, not however being able to ascertain what 

 degree of credit was due to it. At length we were favoured 

 with a pair of these magnificent shells, which were thrown 

 up on the sands at Warren's-point, after a severe thunder 

 storm. They were at the time covered with the Lepas Ba- 

 lanus, Serpula triquetra, and Cellepora spinosa ; and in 

 one of them were found the putrid remains of the animal 

 inhabitant. 



It may also be observed, that no foreign vessels touch on 

 that coast, that no collector of shells lives in that part of 

 Ireland, and that the person who found them and present- 

 ed them to us knew not one shell from another, and won- 

 dered at our exact examination into their history, v. m. 



2. Murex Erinaceus. Hedge-hog Rock-shell. 



Pennant, pi. 79. f. 1 Da Costa, pi. 8. f. 7 Donovan, 

 pi. 35 Dorset Cat. pi. 1-1. f. 7- 



Shell strong, rough, angular, brown or whitish : spires 

 seven or eight, abruptly sloping at the junctions, ending in 

 a fine point ; the primary volution with numerous raised 

 transverse lines ; the rest with generally two strong raised 

 warty circular ribs ; all of them mostly clothed with small 

 concave arched scales placed in an imbricate manner, and 

 furnished with about seven strong longitudinal ribs : aper- 

 ture oval, ending in a short closed tubular canal which is 

 reflected ; outer-lip thick, toothed within; pillar-lip smooth, 

 glossy-white : length nearly two inches ; breadth about one. 



Old shells have the outer-lip very thick, fiat and angu- 

 lar : young shells have the canal open, with the outer-lip 

 thin and striate transversely on the inside, often marked 

 with transverse brown bands : they may be distinguished 

 from the young of Buccinum Lapillus, by the longitudinal 

 ribsj and the abrupt sloping of the volutions to the line of 

 i 2 junction. 



