31 



and Megascolex, which hitherto are only found in the Oriental 

 region. As to the genus Perionyx, we have five species from the 

 Oriental region, while only a single one is described by Michaelsen 

 from Sansibar. Cryptodrilus insularis forms a link between the fauna's 

 of the Malay Archipelago and Australia, for which latter country 

 this genus is characteristic. A remarquable phenomenon is the presence 

 in the Malayan region of the genus Benhamia , of which three species 

 are described in the present paper; they considerably augment the 

 number of species, found out of Africa, where this genus appears to 

 be indigenous. As we can hardly ascribe the presence of these worms to 

 man's interference, Michaelsen's assertion „dass die Benhamien eine sehr 

 geringe Verbreitungskraft haben" appears to be somewhat premature. 



ACANTHODRILIDAE. 



Though Acanthodrilidae are known from different parts of the world 

 viz. Afrika, S. America, N. Zealand etc., no species are described 

 hitherto from the Indo- Malayan regions. 



The specimens, collected by Prof. Weber, all are small worms, which 

 must be ranged among the genus Benhamia, characterized according 

 to Michaelsen's description , by having the setae placed at the ventral 

 side, by the situation of the male pores in a fossa, by the presence 

 (usually) of more than one gizzard, and of an excretory system in 

 the forme of delicate tubules *). I am not quite convinced , however, 

 that those characters are sufficient for a natural subdivision of the 

 genus Acanthodrilus. 



I cannot agree with Michaelsen that Benham's genus Trigaster 

 ought to be cancelled and included into the genus Benhamia; provi- 

 sorily it appears to me preferable to retain both generic names, for 

 Tr. Lankesteri, as Benham has recently pointed out 2 ), is distinguished 

 from about all the Benhamia-species not only by the great extent of 

 its clitellum (XIV to XL), but also by the absence of the intestinal 

 coeca and the penial setae. 



1) Jahrb. der Hamburg. Wissens. Anstalten VI, 1889, p. 6; VII, 1890, p. 3. 



2) Ann. a. Mag. of Nat. History, 1890, p. 41 4. 



