1895.] MB. F. E. BEDDABD ON XEW EARTHWORSCS. 211 



The number of individuals is much greater ; bat the proportion of 

 new species is not so great. The actual number of new species is, 

 however, much greater. Considering that a good many papers 

 have been written upon the terrestrial Oligochjefa of this part of 

 the world bv Michaelsen, Eosa, and by myself, I was unprepared 

 for the very large number of new species whicli Dr. Michaelsen has 

 got together and kindly entrusted to me for description. The 

 collection consisted exclusively of members of the four following 

 families : Lumbricidae, PericHfetidae, Acauthodrilidae, and Crypto- 

 drilidae. Tlie total absence of Eudrilidae is not of course remarkable, 

 except perhaps as regards the genus Endrilas itself. The entire 

 want of Geoscolicidse is much more siogular. Hitherto, however, 

 the only Greoscolicid which has been found south of the Kio G-rande 

 do Sul is the Titanus forr/uesi of Perrier. Xorth of this point the 

 family is apparently one of the most abundant. The Perichstidse 

 are represented only by a single individual, but this family is not one 

 which is common anywhei-e in the South- American continent. 

 Their headquarters, as regards the New World, are certain of 

 the West-Indian Islands. Lumbricidsj are fairly abundant in 

 Dr. Michaelsen's collection ; but then this cosmopolitan familj^ is 

 abundant everywhere. I am convinced that here as elsewhere 

 the Lumbricidae have been introduced. Dr. Michaelsen informs me 

 in a letter that he observed the proportion of Lumbricidte in his 

 gatherings to diminish with the increased distance from the coast ; 

 in cultivated gardens near to the seaboard this family was the 

 most abundant. This fact (which Prof. »Spencer has confirmed for 

 Austi'alia) is an argument for regarding these worms as the result 

 of intercourse between Europe and the countries in question. A 

 fact which obviously points in the same direction is the invariable 

 identity of the exotic species with European or Xorth-Araerican 

 forms. The characteristic indigenous forms of the temperate 

 regions of South America are of the families Acanthodrilidae and 

 Cryptodrilidse. Both of these families occur in Central and Xorth 

 America as well ; but they are not by any means relatively so 

 abundant in the south temperate region of the continent. More- 

 over, the genus Acanthodrilus (s. s.)is only found in this part of the 

 world, being represented in the tropical and north temperate parts 

 by Benhamia, Trigaster, and Dlplocardia. An examination of this 

 collection, in fact, seems to coufirui what previous researches upon 

 the earthworm fauna of America appeared to indicate — namely, that 

 it is possible to divide the Neotropical region into a tropical and 

 a temperate section. The former is characterized by Greoscoli- 

 cidae, the latter by the genus Acanthodrilus. But in this last genus 

 we have a correspondence between temperate South America and 

 New Zealand. This correspondence is also emphasized by the great 

 prevalence of Microscolex in South America and its fairly common 

 occurrence in New Zealand. The Cryptodrilidae collected by 

 Dr. Michaelsen belong exclusively to this genus ; and they are 

 quite as abundant, though perhaps there are not so many species as 

 the AeanthodrilidEB. Microifcole.v, however, is not so restricted to 



14* 



