403 MANUAL OF THE MOLLUSCA. 



the species of Stoastoma, Sag da and Geomehmia, the small subgenus Lucidella, 

 the AJcadias and the mass of beautiful Cyclostomas with a decollated spire and 

 fringed lip {Clioanopoma, AdarasieUa, Jamnlcia, Chondropoma, part, and 

 Cistida, part.* The solitary Clausilia is found in P. Rico, the Balea in Haiti, 

 and the Tornaiellina in Cuba ; Stenopus is peculiar to St. Vincents. Ber- 

 muda has 4 Helices of which, one is common to Texas and one to Cuba- 

 The Choudropomas are found in Cuba and Haiti. 



The West Indian Achatince belong to the subgenera Glandina, Liguus, 

 and Spiraxis ; the Bulimi are sharp-lipped and mostly small and slender 

 {Subulina, Orthallcus). Helix (Sagda) epistylium, H. Carocolla, and Succi- 

 nea (Amphibulima) patida are characteristic forms. 



Although connected with Florida by the chain of the Bahamas, and with 

 Trinidad by the Lesser Antilles, very few species are common to the mainland 

 of either North or South America ; the relation is generic chiefly. 



The LimacidcB are represented by Vaginuhis (Sloanei) ; and in the fresh- 

 waters there are species oi Physa (3,) Ptanorhis,%, Ancylus and the peculiar 

 Gundlachia, Valvata pygmcea, Anepullaria (fasciata), Paludestrina (minute 

 sp.) Hemmnus, and 2 sp. of Pisidium. 



In the brackish-waters are Cerithidmm, Neritina (e. g. meleagris, pupa, 

 virgiuea, viridis), Melampus (coniformis) and Pedlpes quadridens. 



22. Columbian Region.t ^ 



The tract shaded in the map comprehends several minor regions ; 1, the 

 rainy and wooded states of New Granada and Ecuador ; 2, the elevated and 

 nearly rainless province of Venezuela, with a flora like that of the higher regi- 

 ons of the Andes ; 3, the Guianas, including the Valley of the Amazon, where 

 the forests are most luxuriant, aud raiu falls almost daily (amounting to 100 

 or even 200 inches in the year). Most of the low lands, like those of the 

 Mexican Province, belong to the " Cactus Region" of botanists, and have a 

 mean temp, of 68° — 84°. Landshells are abundant in the forests and under- 

 wood of the lower zone of the mountains, where the temperature is 10° less 

 and the rains more copious. Bulimi are the predominant forms, especially 

 the succinea-shaped species, (e. g. B. succinoides). 



Helix 37 Pupa 7 Cistula 1 



Streptaxis 3 Clausilia 3 Bourciera 1 



Bulimus ' 45 Cylindrella 1 Cyclotus 8 



Succiuea 9 Yitrina 1 Adamsiella 1 



Tornatellina 1 Llmax 1 Helicina 6 



Achatina 10 Choanopoma 2 Trochatella 1 



Glauclina 5 Cyclophorus 2 



* A magnificent collection of Jamaica land shells has been presented to the British 

 Museum by the Hon. E. Chitty whose researches were conducted with the late Prof. 

 C. B. Adams. 



+ In 1821 the states of New Granada, Venezuela and Ecuador united to form the 

 " Columbian Republic," but dissolved again in 1831. 



