NELSON ON THE BAHAMAS. 



211 



ing. 



Tubes from -^ inch 



to 2 inches in diameter. 



plants, consohdates and completes the chalky soil. This, like the soil 

 originating with Acetabularice, Spongillce, &c. amongst the mangrove 

 roots, is well mixed with carbonaceous matter and well adapted to 

 support vegetation. 



In a fossil condition the traces of 

 Fig. 4. Koot-like tubular plants are obscure ; at some places, how- 

 bodies passing through g^er, the rock is extensively traversed 

 the strata at Cay bal, ^j contorted, irregular, stony tubes, of 

 and exposed by weather- various diameters from yL to l^ inch, 

 exhibiting an appearance of having been 

 aggregated round long slender roots, or 

 even stems, that have since perished. 

 These pass through the strata or not 

 indifferently ; sometimes they are ex- 

 posed by the waves and weather and 

 stand out as disengaged masses of tubes 

 (see fig. 4), as in the low cliff under 

 Gun Cay Lighthouse, and elsewhere. 

 Rudely cylindrical bodies also, from 9 

 to 12 inches in diameter, generally im- 

 bedded in and filled with red-earth- 

 rock, appear in transverse sections along 

 the road-cuttings ; their character is very 

 equivocal, even more so than those at 

 Bermuda*. Small root-like bodies also 

 are often imbedded in the red-earth- 

 rock. Nearly all the Bahamas abound 

 in these tubular concretions. 

 Of animal organic bodies, the Coralsf are by far the greatest 

 contributors, both as affording materials and as retaining loose sand, 

 &c. mechanically. Of these the MadreporaX (in the sense used by 

 Ellis) is the most important. It occurs in mass and affords sand. 

 Zoanthe {Z. sociata and an unnamed species, which is much more 



cellular fibres. Capt. N. observes, that when fresh, the moss has a strong odour 

 of iodine. 



* Loc. cit. p. 115. 



t Seas may be prolific, says the author, in zoophytes, dispersed in small groups 

 or low sloping banks, without their having any very obvious tendency to form 

 abrupt reefs, which last, I believe, are not now to be found in the Bahamas. In 

 Hanover Sound, for instance, the bottom is a zoophytic garden of most interesting 

 subjects, but there is very little appearance of the labyrinthine reefs that obtain 

 in Bermuda, especially along its north-east and south-east portions. 



X M. cerebrum ; 2 or 3 varieties. 

 M. porites, branched and massive. 

 M. undata. 

 M. astraea. 

 M. rotulosa. 

 All abundant except M. undata. 



Near East Point, New Providence, occurs a remarkable accumulation of broken 

 Madrepores, imbedded in a dark grey rugged rock, at and a httle above high- 

 water mark, which, however, does not belong to the coral-reef basis. 



M. galaxsea. 



M. muricata ; 2 or 3 varieties. 



M. areolata. 



M. labyrinthica. 



M. phrygia. 



