338 MOLLUSOA. 



the following year, the mussels on it were not more than | an inch in 

 length. 



Sept. 1, 1843. The light-ship was moored at Holy wood Bank, and on 

 being brought into dock, on Nov. 15, 1844, to have her bottom cleaned, it 

 was covered with full-grown mussels, which Avere carried away by jjersons 

 to eat. If we knew the size those were when they moored themselves to 

 the ship, the problem is solved of how long they are attaining full size. 



July, 1845. Mr. Hyndman showed me mussels nearly 1| inch long, of 

 which quantities were taken from the bottom of the pilot-boat after its 

 being nine months afloat. 



Genus Crenella. 

 C. (lecussatti, Laskey. 

 A few odd valves di'edged in rather deep water — shelly bottom — in 

 Strangford Lough, Aug., 1837, Mr. Hyndman and W. T. 



Genus Modiola. 

 M. vulgaris, Br. 



Common on the North and North-East coasts in rather deep water on 

 muddy and shelly ground ; used as bait by fishermen in some places, but 

 not commonly as human food ; called horse-mussel. Apparently scarce or 

 wanting in such of the bays of Mayo and Galway as were dredged by 

 our party in 1840. 31. (J ihhsii took, its place in some localities. 



3Iodiola vuli/aris. According to my journal, note of Dec. 14th, 1837, 

 I find that full-grown individuals lived without water four days in a 

 warm room, and that smaller individuals lived under similar circum- 

 stances eight days. 



3f. tulipn, Lam. 



Very rare. Belfast Bay, Mr. Hyndman and W. T. Malahide, Dublin 

 coast, one or two specimens. Dr. Lloyd. Portmarnock, very rare, Mr. 

 Warren. Birterbuy Bay, Dr. Farran. In or near Bantry Bay, Mr. 

 M'Andrew. 



31. Gihhsii, Leach. 



Dredged in Clew and Killery Bays by our party in 1840, 3 — 12 

 fathoms. 31. Gihhsii is noted in Mr. Barlee's list of Birterbuy Bay 

 species, with a query as to its being a variety of M. vulgaris. Youghal, 

 very rare, Dr. R. Ball. 



31. discrepans, Mont. 



" Found on oysters in Dublin Bay," (O'Kelly) ; I have seen specimens 

 from thence in Mr. Warren's collection. Larne Lough, not uncommon. 

 Donaghadee, 8 to 10 fathoms. Dr. Drummond. Wicklow and Wexford 

 coasts ; Youghal, Dr. R. Ball. Cork harbour, Mr. Humphreys. Dredged 

 in Killery and Clew Bays, in 1840. Birterbuy Bay, Dr. Farran. This is 

 a much less common species than the following. 



31. nrarmorata, Forbes. 



Dublin coast and Strangford Lough, Brown. Common on the North 

 and North-East coasts, more especially embedded in various species of 

 Ascidia : found loose also, sheltering among Balani and other excre- 

 scences on oysters, &c. 



