608 PROCEEDINGS OF THE ACADEMY OF [NoV., 



Parham, New Work, the salt in the water was only 14.7 parts per 

 100,000 in 1911. On the other hand, in the raised beach deposits 

 in the east of the island the content of sodium chloride in the water 

 is often as much as, or more than, that of the Cassada Garden well, 

 and this is doubtless true of all districts recently covered by salt 

 ponds, although they now may show no evidence of recent sub- 

 mergence. 



The marine shells found scattered through these shell beds are 

 apparently all recent species; they include many gastropods and a 

 much larger number of pelecypods. A few specimens were gathered 

 and some of the larger species simply noted. Among the gastropods 

 the large Strombus gigas L. was occasionally seen, also Melongena 

 melongena L., and Livona pica L. were often encountered. A few 

 specimens of Purpura were seen and P. deltoidea Lam. was collected, 

 as was also Bullaria occidentalis (A. Ad.) and Modulus modulus (L.). 

 The pelecypods collected include Area chemnitzii Phil., Cardium 

 muricatum L., Chione cancellata L., and two varieties of Anomalo- 

 cardia flexuosa L., but many other species were seen, especially 

 Codakia orbicularis (L.) and Codakia orbiculata Mont. A limpet, 

 Fissuridea barbadensis Gmel., was observed. Land shells, particularly 

 Bulimulus guadalupensis Brug., are plentiful in the soil mixed with 

 the marine shells, they have probably been recently introduced into 

 this deposit from forms living in the Central Plain when it was first 

 cleared and settled. 



8. Raised Beaches, Horizontal Marls of Purves. 



Along a part of the north shore of the island and also along the 

 northeast shore down to St. George's Church there are, at certain 

 places, definite horizontal deposits, consisting of marl with marine 

 and land shells often mixed together, imbedded in the deposit. These 

 have been described by Purves as the horizontal marls, and are well 

 developed in the vicinity of St. George's Church. They are not seen 

 at any great elevation above the present sea level, not more than 

 10-12 feet, and are probably old salt pond deposits. The one at 

 St. George's Church contains plentiful remains of land shells mixed 

 with marine species. Here I saw Pleurodonte formosa (Fer.) with the 

 deeper pigment bands still showing their color; although the finer 

 color pattern characterictic of the recent shell is lost. Dry)nceus 

 elongatus Bolt, was also plentiful, but the specimens of P. Jormosa 

 (Fer.) outnumbered the Drymceus about three to one. This Antigua 

 species of Pleurodonte was only known alive, to the local collectors 



