448 Miscellaneous. 



The ovoid phaiyngeal swelling extends from the third to the fifth 

 segment ; it is followed by a straight cesophagns, which, in seg- 

 ments 10, 11, 12, and 13, presents four dilatations, taking the place 

 of the gizzard. The intestine, properly so-called, commences at the 

 fourteenth segment. In the anterior region (segments 5 to 9) the 

 cesophagus is covered laterally and dorsally by voluminous glands, 

 which decrease posteriorly ; the smallest is situated in the ninth 

 segment. I regard these as homologous with the septal glands 

 discovered by Yejdovsky in the Enchytrseidae. Notwithstanding the 

 place which they occupy against the intestine, these organs are not 

 digestive glands ; they open on the outside of the back, and I think 

 that it is to their secretion that the luminous property of the Photo- 

 drilus must be attributed. The dissepiments do not always corre- 

 spond exactly with the limit of two consecutive segments. Thus 

 the ninth septum is not situated between the ninth and the tenth 

 segments, but it is attached to the intestinal wall, towards the 

 middle of the tenth ; in the same manner the tenth, eleventh, and 

 twelfth septa start from a lateral insertion situated a little below the 

 lower limit of the tenth, eleventh, and twelfth segments, and sur- 

 round the intestine towards the middle of the eleventh, twelfth, 

 and thirteenth segments. The same fact has been remarked by 

 Horst in Moniligaster Houtenii. 



The circulatory apparatus differs little from that of the Pontodrili. 

 The lateral hearts are situated in segments 10, 11, and 12, The 

 ventral vessel is divided, towards the middle of the 8th segment, 

 into two lateral ventral branches, which, at first very widely sepa- 

 rated, converge in segments 5 and 4, and are then directed laterally 

 into segments 2 and 1, to form a fine vascular plexus in the 

 cephalic lobe. 



There are two pairs of testes. They are large, very vascular 

 glands, which occupy the upper part of segments 11 and 12. The 

 ovaries are situated in the thirteenth segment. The animals which 

 we have studied not being at the period of sexual activity, the male 

 genital apertures were not very distinct. The apertures of the ovi- 

 ducts were to be seen very clearly on the lower surface of the 

 fourteenth segment, in the form of two little fissures, slightly 

 oblique from without inwards. The cojmlatory pouches, situated 

 in the ninth segment, have a small accessory sac, as in the Pon- 

 todrili. 



In certain individuals, in the twelfth and sometimes in the thir- 

 teenth and eighteenth segment, besides the eight ordinary setae, two 

 complementary setse may be seen, situated lower down than the 

 others and placed outside the lower ventral rows ; sometimes one of 

 these setae is replaced by a bundle of four setae, and that sometimes 

 to the right, sometimes to the left. Horst seems to have met with 

 similar tetrachetal bundles in the Mliinodrilus Zenkatei. Are these 

 penial setae in retrogression ? 



The short description which Duges has given of his Lnmhricus 

 phosplioreus * may apply to the Photodrilus. Duges found this 

 species in the tan of a hoth( use ia the Jardin des Plantes at 

 * Ann. des Sc. Nat. 2" serie^ t. viii. p. 24 (1837). 



