DESCRIPTIONS OF GENERA AND SPECIES 351 



of the structures in question ; thus he makes no mention of the salivary glands, which Vejdovsky 

 said were inconspicuous ; the rudimentary character of these glands distinguishes the species from 

 R. leptodera and H. dicksonii. From d'Udekem's account and figures the fourfold division of the 

 oesophageal gland is not apparent ; the whole structure, indeed, is described as a kind of muscular 

 stomach; Vejdovsky, while naturally improving upon the account given by d'Udekem, did not 

 recognize that the supposed stomach was really formed out of four diverticula of the oesophagus, 

 a fact which was later demonstrated by Michaelsen (1). These four glands lie in the eighth segment. 

 They are simple diverticula of the gut, with a lining of ciliated cells ; the walls are a little folded, but 

 there is in the figures of Michaelsen, at any rate, no trace of the intra-cellular lumina described by 

 the same author in Buehholzia. 



The dorsal vessel springs from the perioesophageal plexus in the ninth segment; 

 it has three heart-like swellings in segments vii, viii, ix ; the brain is longer than 

 broadj and broader behind than in front; it is concave anteriorly, and is markedly- 

 notched behind ; the funnel of the sperm-duct is rather small ; the sperm-duct is 

 long and coiled. The spermathecae consist of a pear-shaped distal part and of a duct 

 of about the same length, which is somewhat dilated at its opening on to the exterior. 

 d'Udekem has remarked that these organs present the appearance of glands attached to 

 the alimentary canal, thus foreshadowing the discovery of Michaelsen that they open 

 into it. The nephridia are said by d'Udekem to commence in the fourth segment. 



(2) Henlea leptodera (Vejdovskt). 



Arcliienehsrtraeus nasutus, Eisen, Ofv. Svensk. Akad., J 878, No. 3, p. 72. 



Enchytraeus leptodera, Vejdovsky, Ench. 1879, p. ^^. 



E. (Archienehytraeus, Eisen) leptodera, MiCHAELSEN, Ench. Mob., 1886, p. 46 et 



passim. 

 Archienehytraeus leptodera, Rosa, Boll. Mus. Zool. Torino, 1 887, No. 29. 

 Henlea leptodera, Michaelsen, Abh. Nat. Ver. Hamb., 1889, p. 32. 

 H. nasuta, Michaelsen, ibid., p. 32. 



Definition. Length, 20 mm.; number of segments, 60; setae straight, ^to J. Two oesophageal 

 glands, with simple lumen. Hah. — Europe; Sibevia. Terrestrial. 



Michaelsen considers that the present species is the same as EisEn's Archienehytraeus affinis; 

 this opinion is based upon an actual examination of both species by Michaelsen. Eisen did 

 not mention the gut-diverticula, which are nevertheless, according to Michaelsen, present, and 

 of exactly the same form as in H. leptodera. On the other hand, it jnay be pointed out that 

 the brain appears from the figures to be a little different in form in the two 'species.' In 

 H. leptodera the brain is more sharply notched behind than in the form called by ElSEN Archi- 

 enchytramis affinis (cf. Vejdovsky, 3, PI. x. fig. i, and Eisen, 13, PI. vi. fig. 2 c). As has already 

 been mentioned, however, the brain is susceptible of alterations in form, according to the state 

 of contraction of the muscles attached to it. Eisen has remarked that the species 'affinis' is very 



