300 CYPRINIDJE. 



line Crag ; and it is not uncommon in a layer of brick- 

 earth near Christiania containing shells of arctic species. 

 Lilljeborg has dredged it as far north as Molde fiord near 

 Christiansund ; and, according to Maravigna and Phi- 

 lippic it occurs as far south as Sicily. Many instances 

 may be enumerated of its inhabiting the Scandinavian 

 as well as Mediterranean seas, at depths varying from 

 15 to 80 fathoms. 



By far the best account which has been given of the 

 animal is that by the Rev. James Bulwer, in the second 

 volume of the ' Zoological Journal.' He procured a 

 considerable number of live specimens, taken by trawl- 

 ing in very deep water on the east coast of Ireland. 

 Although this account has been twice republished, it is 

 so interesting and evidently so accurate, that I cannot 

 refrain from inserting here a portion of it. He says, 

 " On being placed in a vessel of sea-water the valves of 

 the shell gradually opened, to the extent represented in 

 the drawing [which accompanies the description] : the 

 feelers or ciliated fringe of the upper* orifice of the 

 mantle moved slowly, as if in search of animalcule. 

 Having remained in this situation about ten minutes, 

 water was ejected with considerable force from the 

 lower [upper or excurrent] orifice, which had till now 

 remained motionless. The expulsion of the water ap- 

 peared to be effected by a sudden contraction of the 

 muscles, because this was never done without the valves 

 nearly closing at the same instant. After a few seconds 

 the valves gradually returned to their open position, and 

 remained quiescent as before, till the water was again 

 ejected with a jerk : this alternating process was re- 



* [The Isocardia is delineated in a horizontal position, and this orifice 

 being next to the foot and furthest from the beaks is the lower or incur- 

 rent orifice.] 



