DESCRIPTIONS OF GENERA AND SPECIES 691 



The first two sentences in these definitions serve to separate both genera from 



Allunis and Dendrobaena ; the latter is thus defined: 



Dendrobaena. 'Tubercula ventralia in segmento 14. Setae ubique aequo intervallo 

 distantes exceptis duabus summis quarum intervallum aliquanto majus 

 est. Lobus cephalicus tres partes segment! buccalia occupans.' 



These definitions obviously rest upon rather slender differences. Those who have 

 followed EISEN have usually accepted his genus Allolobophora, but not allowed 

 Dendrobaena ; in this way the species belonging to the three genera will be separable 

 into two series according as to whether the buccal lobe does or does not completely 

 divide the buccal segment. This is, for instance, the position taken up by ROSA. 

 in his eai'lier paper upon the Lumbricidae of Italy. 



OERLEY has, however, proposed a still further division of the Lumbricidae. He 

 resuscitates the old name of Enterion for a portion of Lv/mbricus ; and divides 

 Allolobophora of EISEN into Allolobophora, Octolasion, and Aporrectodea. Octolasion is 

 used for those species with setae in eight rows ; the two other genera have paired 

 setae, but in the genus Allolobophora the tubercula pubertatis form a continuous 

 streak ; they are separate in Aporrectodea. 



FBIEND has lately revived the name of Dendrobaena, using it as one of three 

 subgenera (the others being Lumbricoidea and Mucida) of Allolobophora. 



The last attempt at subdividing Allolobophora is by ROSA. He allows four sub- 

 genera of Allolobophora, viz. Allolobophora, Notogama, Dendrobaena, and Octolasion ; 

 they are characterized as follows : 



(1) Notogama. Four pairs of sperm-sacs, testes and funnels free ; spermathecae opening 



near to dorsal median line. 



(2) Dendrobaena. Three pairs of sperm-sacs, testes and funnels free ; spermathecae 



opening in front of dorsal setae. 



(3) Allolobophora. Four pairs of sperm-sacs, testes and funnels free ; spermathecae 



as in last. 



(4) Octolasion. Four pairs of sperm-sacs, with four seminal sacs enclosing testes and 



funnels ; spermathecae opening in front of setae. 



To these he appears to be disposed to add a fifth for those species in which there 

 are only two pairs of sperm-sacs ; he admits also that there are a number of other 

 species which cannot be grouped in either subgenus. In the above definitions 

 colour and arrangement of the setae are left out because they are not constant in 

 a given subgenus ; for example, in Notagama the setae are paired or more distant, 

 and the pigment may be present or absent in the skin of the back. 



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