MARINE ZOOLOGY OF ARRAX. 271 



gress, and a few of the valves, were secured for private 

 cabinets; and pieces of the bored timber were given to the 

 museums of Glasgow College and of the Andersonian Uni- 

 versity. 



The most abundant species of Trochus on these western 

 shores is T. umbilicatus, which, with T. cinerarius and T. 

 tumidus, may be procured in any quantity on Holy Island. 

 Here also the following shells are not uncommon: Acmcea 

 testudinalis, Kellia rubra a minute bivalve attached to the 

 dark low growing plant, Lichina pygmcea, which overspreads 

 the rocks near the sea; Patella athletica, P. pellucida, Tapes 

 decussata, with different species of Littorina, and other equally 

 common and widely diffused forms. In the sands, at Lam- 

 lash, at low water, Mactra sollda and M. subtruncata are 

 plentiful. But, leaving the coast line, and letting the dredge 

 drop in about ten fathoms, at the north end of Holy Island, 

 or between the north point of the island and the pier, a 

 peculiarly interesting shell may be collected in large quan- 

 tities Lima hians the inhabitant of which constructs and 

 occupies a nest. The shell is of delicate texture, and, when 

 deprived of extraneous matter by careful washing, is entirely 

 white, and, being graceful in form, is an acquisition to an 

 ornamental cabinet. It is desirable, however, to preserve 

 specimens of the nest as well as of the shell, and to allow 

 both to remain, as far as possible, in their natural position. 

 The nest is formed of materials collected at the bottom of the 

 sea either pebbles, or broken shells, or both shells and 

 pebbles; and these are brought into a mass and bound 

 together by a glutinous thread secreted by the animal. 

 Sometimes the Lima is solitary having built a house simply 

 for itself ; but, generally in Lamlash Bay, the dredge brings 

 \ip large patches of this compacted debris, in which will be 

 found a colony living in apparent comfort, security, and 

 friendship each individual, however, having a separate and 

 snug berth. A supply of specimens may be secured in a few 

 moments. The animal is also a 'beautiful object in the water 



