352 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



preceding cases, and they are absolutely free from encrusting 

 matter of any kind. They are all well-rounded, smooth, and 

 polished, and their composition is very varied. Before the 

 origin of these stones can be ascertained, much purely 

 geological work still requires to be done. 



The shells and comminuted particles are numerous, although 

 the bulk of this deposit is made up of quartz sand. There are 

 very few complete valves, the majority being ground down 

 to form a fine calcareous sand. The genera identified are as 

 follows : — Nucula, Cardium, Tellina, Trochus, Emarginula, 

 Venus, Turritella, and Ceriihium. 



The quartz sand, which composes by far the greater part 

 of the deposit, is formed of the varieties rock crystal and 

 milky quartz. The grains are all more or less rounded, but 

 many of them are fairly angular. 



Other organic remains in the sample are echinoid spines 

 and pieces of the test, and many polyzoa. 



IX. [17] 17/4/13. Half-way between Bahama Ship and 

 the "Hole." 



The sample obtained from this station is a very coarse 

 one, composed of small pebbles, quartz grains, and organic 

 debris (shells). The greater part of the deposit is made up of 

 shells which, although mostly broken, are in large pieces, 

 constituting a very coarse sand. There is also a large pro- 

 portion of finely comminuted matter. The genera identified 

 are as follows : — Pecten, Buccinum, Leda, Pectunculus, Nucula, 

 Cardium, Tellina, Solen, Balanus, and Eulimella. Among the 

 other organic remains were found the spines of echinoids, 

 comminuted particles of the rays of ophiuroids, and several 

 specimens of Echinocyamus pusillus. There is no suggestion 

 of mud or any finely reduced matter, such as is sometimes 

 found mixed with these coarse deposits. 



