40 SUMMARY OF CURRENT RESEARCHES RELATING TO 



richly vascular ; the setae are not bigcminate but separated as in 

 Pontodrilus. There is no distinct buccal segment, and only one pair of 

 oopulatory pouches. The clitollum extends from the thirteenth to the 

 seventeenth ring, the female orifices are on the fourteenth, and the male 

 on the eighteenth. The digestive tract has a protrusible proboscis, and as 

 it comes and goes one may see on the lower surface of the buccal segment 

 a tuft of long clear filaments which are very delicate, and are sometimes 

 transversely striated. It is possible that they are the homologues of the 

 cylindrical rods described by Prof. Perrier in the interior of Pontodrilus, 

 or they may be broken muscular fibres. The gizzard is replaced by 

 four swellings ; the oesophagus is invested dorsally and laterally by 

 large glands which decrease in size from before backwards ; these are 

 regarded as being homologous with the septal glands described by 

 Dr. Vejdovsky in the Enchytraeidae. Notwithstanding their position, 

 these are not enteric glands, and they open on the dorsal surface ; the 

 author thinks that the photogenic property of Photodrilus is due to the 

 secretion of these glands. The circulatory apparatus differs little from 

 that of Pontodrilus; there are two pairs of testes, and one pair of 

 ovaries. As Duges' worm was found in hot-beds in the Jardin des 

 Plantes at Montpellier, and the Wimereux specimens in a cultivated 

 garden to which earth had been brought by a horticulturist, it is 

 probable that the species is not French but exotic. 



Enchytraeidae. * — Dr. W. Michaelsen has made a preliminary 

 systematic study of the interesting family of Enchytraeidae. His system 

 is as follows : — 

 Setae S-shaped. 



Head-pore large, at or near point of head-lobe. No salivary glands. 

 Colourless blood. Dorsal vessel with heart. Vas deferens 

 short ; at most, eight times longer than the seminal funnel. 



Mesenchytraeus Eisen. 



Head-pore small between head-ring and lobe. Long vas deferens. 



No salivary glands. Blood yellow to red. Dorsal vessel without 



heart. Pachydrilus Claparede. 



Short salivary glands opening into oesophagus. Blood colourless. 



Dorsal vessel rises from a diverticulum in VII. segment. 



Buchholzia Michaelsen. 

 Setae straight, with only a slight internal curvature. 



Head-pore small between head-ring and head-lobe. Blood colour- 

 less. Dorsal vessel without heart. Salivary glands usually well 

 developed. Vas deferens long. Enchytrseus Henle. 



Setae aborted. 



Head-pore large at apex of head-lobe. Blood colourless. Dorsal 

 vessel with heart. An unpaired salivary gland on the intestine. 

 Vas deferens long, more or less regularly spiral. Seminal sac 

 large, intruding freely into the body-cavity, not coalescent with 

 the gut. Anachseta Vejdovsky. 



Parasite of Telphusa.f — Signor W. Drago has described a parasite 

 which Prof. B. Grassi found some time ago on the gills of Telphusa 

 fluviatilis in considerable abundance. It was at first suspected to be a 

 Branchiobdella, but was soon recognized as an oligochaete. It is in fact 



* Arch. f. Mikr. Anat., xxx. (1887) pp. 366-78 (1 pi.). 

 t Bull. Soc. Entomol. Ital., xix. (1887) pp. 81-3. 



