1 38 2.] Recent Literature. 5 8 1 



and geographical distribution. The facts pertaining to the latter 

 phase are further illustrated by two maps, showing the distribution 

 of the species by islands, and in individual islands. They are, 

 the author states, the work of Mr. Andrew Garrett, a resident of 

 Huaheine, from whom we arc promised further descriptions of 

 species based upon the MSS. of the late \V. II. Pease, and his own 

 copious collections. From the facts brought out by Dr. Hartman 

 it appears that Partula illustrates the influence of environment as 

 do but few other genera of land shells. It is true that some of 

 the species are said to be remarkably uniform in specific charac- 

 ter and somewhat widely distributed over the islands in which they 

 do occur, but the instances of variation, when away from the 

 centers of distribution, appear to be much more numerous. To 

 this fact must be attributed some of the vast quantity of synono- 

 my indicated. Another peculiar feature is the common occur- 

 rence of hybrids amongst certain forms " the result of the union of 

 proximate species:' Dr. Hartman states that hybridization even 

 occurs between the arboreal and ground species, and here is 

 another fruitful source for re-description, as in Achatinella, and 

 we might add Goniobasis as found in the southern United States, 

 there is a marked mutation of species consequent on change of 

 food and station. " It often happens that the gravid female's are 

 Washed by heavy rains from a favored position to drier levels, 



helices of the United States. e.<r. Zomtes frhi/>i!is t Z. caducus, 

 Z. capnodes, Z fuliginosus, and Z. he. -■/ oatit s. which, without doing 

 violence to any racial principle, may be perhaps considered ex- 

 treme geographical varieties. A fact calling for deep regret in 

 connection with American conchology is the utter neglect of 

 authors thus far, in studying the habits, the food, and the distribu- 

 tion of certain forms. We are convinced that a vast deal of work 

 remains to be done in this direction; a work which Hartman has 

 performed for Partula; a work which will sensibly limit the num- 

 ber of accepted species. Especially will this be true of the two 

 great fresh-water families of our country, Unionicte and Strep- 

 omat.dae. In the case of Partula. Dr. Hartman finds the lingual 

 dent.tion to vary within rather wide limits in the same species, a 

 tact winch apparenth- indicates that the basis for final and ideal 

 classification does not lie therein. It is to be hoped that his un- 

 nvaled facilities will induce this author to further elaborate the 

 data bearing on the evolution of forms, of which he now gives us 

 vague but suggestive hints. In summing up we should not fail 

 to remark that of one hundred and seventy-four species enumer- 

 ated, all go into synonomy save seventy-three, or over fifty per 

 cent The genus, by the way, is declared to be confined to the 

 r acinc islands. " They have never been found at the Sandwich 



