Th c Ea rth worm s of Ire I a 7id. 273 



Allurus, Kiscn. 



The genus Allurus was first created by Eisen in 1S73, when he pub- 

 lished in the "Ofversigt af Kongl. Vetenskaps Akad." No. 8, p. 43 et seq., 

 a capital summary of the knowledge then existing respecting the Earth- 

 worms of Scandinavia. Eisen's one fault lay in placing too much stress 

 on the shape of the lip, too little on internal structure. He was right, 

 however, in separating Allurus from Lumbricus and Allolobophora, for 

 while the latter have the male pore on segment 15, in Allurus this 

 important organ falls on the 13th segment— a most valuable and distinc- 

 tive characteristic. Eisen's summary of the genera may here be pro- 

 fitabl}' reproduced. 



A. Setae ubique binae approximatae : 



I. Tub. ventr. in segm. 14 [ :i= 15 English method] pone segm. 

 buccale. 



1. Lob. cephal. postice segm. buccale in duas partas dividens 



. Ljunbricus. 



2. Lob. cephal. postice segm. buccale non dividens 

 Allolobophora. 



II. Tub. ventr. in segm. 12 [ = 13 English method] pone segm. 

 buccale . . . Allurus. 



B. Setae aequo intervallo distantes, exceptis duabus summis, quarum 

 intervallum aliquanto majus est . . . Dendroboena. 



Here we find Allurus distinguished from its predecessors only by the 

 position of the male pore. The generic diagnosis is brief and simple : — 

 "Tubercula ventraliain segmento 12 [= 13]. Corpus antice cylindricum, 

 postice quadrangulum, setae binae approximatae." It was this quadran- 

 gular shape of the hinder or tail portion which suggested the name of 

 the genus, and since 1873 there has been no dispute about the nomen- 

 clature. 



It must not, however, be supposed that the worm or worms included 

 in the genus Allurus by Eisen had previously been unknown. We find 

 allusions in the works of several authors in the early part of this century 

 which distinctly point to the species now under review. Allurus was 

 unknow^n to Linnaeus. The first writer, so far as I can ascertain, who 

 gives us any information respecting this worm was Sa\dgny, who, 

 discarding the Linn^ean term Lumbricus, adopted the Graecised word 

 Enterion (the Enteron of Aristotle). In Cuvier's " Histoire des Progres des 

 Sciences Naturelles," he calls it Enterion tetraidrum, or the Square-tailed 

 Worm. Duges, the same year, gave an account of a worm in the Annales 

 des Sciences Naturelles, which he named Enterion amphisbcena. His reason for 

 adopting the latter or specific name is to be found in the fact that the 

 worm he was describing could go as readily backwards as forwards, after 

 the fashion of the serpent of which Lucanus sang. 



Nine years later Duges wrote again on worms in the same periodical, 

 but put his worm by the side of that of Savigny, and spoke of them as 

 distinct species. He now speaks of them under the term Lumbricus, 

 and names them L. tetraedriis and Z. amphisbcena. Of the first he says 



