92 



Trochus acinosus. Testa solida, convexo-conica, seruginosa, 

 seriebus 4 papillarum insignis et lineolis capillaceis volvenlibus 

 ubique insculpta; serie antica majori : spira anfr. 6 planiusculis, 

 ultimo acutangulato : basis excavata, cinerea, filis concentricis 

 fuscis cincta ; interspatiis indentatis ; regione umbilicali infundi- 

 buliformi et costis duabus tri-partita : apertura rhombea ; colu- 

 mella laevi, contorta ; labro simplici, perobliquo. Diam. f , alt. f 

 poll. Hah. New Zealand. 



The peculiarities of this species are, the series of tubercles on 

 the delicately lineated ground, the excavated base with its thread- 

 like unbeaded lines, and the two white ribs in the umbilical pit. 

 May be. compared with T. vernus, Chem. 



Trochus elisus. Testa parva, elevato-conica, imperforata, 

 cinerea: spira anfr. 6 declivibus, sutura fossali valde profunda 

 discretis, costulis transversis granosis tribus (quorum interme- 

 diani minore) cincta, interspatiis clathratis : basis convexa, cos- 

 tulis clathratis insculpta : apertura subcircularis ; columella gran- 

 ulata ; labro intus sulcato. Diam. f, alt. ^ poll. Dredged at 

 Singapore. 



Distinct from any described species. Its markings are deeply 

 sculptured, and its peculiar sutural region is a character which 

 cannot fail to be noticed at first glance. It is quite probable that 

 it may be colored differently when quite fresh. 



Mr. E. C. Cabot read a paper giving an account of some 

 researches he had made during the last autumn, in company 

 with Mr. Desor, to determine the fact of the constant pres- 

 ence of fresh water in Dune sand and sand spits. These 

 researches were conducted at Cape Cod, which they visited 

 for that purpose in the U. S. Surveying Steamer Bibb, 

 under the command of Lieut. Davis, with whose assistance 

 they were made. 



In every instance where there was a body of sand above the 

 tide level, with salt water on opposite sides, or entirely surround- 

 ing it, fresh water was discovered on digging to a moderate 

 depth. Thus at Monomoy, a long, low island of sand, south of 

 Cape Cod, fresh water was found at its highest part, at a depth 

 of two feet. On the beach, at the line of high water, it was 



