792 RECORD OP CURRENT RESEARCHES RELATING TO 



segment they approacli the middle line, and the broad ciliated surface 

 of the cephalic region is converted into a narrow but deep ciliated 

 groove. It was not found possible to detect any peripheral nerves. 

 The muscular system is arranged very much as in Polygordius. 



The enteric canal extends to the hinder end of the body, but no 

 rectal division could be made out in it. Just behind the mouth 

 there opens into the oesophagus a muscular organ of a complicated 

 form, and terminating blindly in a chitinous vesicle very similar to 

 the same organ in Polygordius ; it has a function which still remains 

 to be discovered. 



In the first trunk-segment there is a broad dorsal vessel, which in 

 the posterior region of the head is enlarged into a contractile bulb ; 

 this consists of a simple membrane formed of flat, doubly-granular 

 cells. By rhythmical contractions the bulb drives the colourless 

 blood into a narrow, thin-wallcd vessel, which reaches as far as the 

 frontal ganglion, and there opens into a transverse branch, which is 

 continued on either side into a tentacular vessel. From the cavity 

 into which these open, the blood is carried away by another thin- 

 walled vessel. A transverse venous plexus is formed behind the 

 frontal ganglion, and from thence two ventral veins pass into an un- 

 paired one. The bulb already mentioned and the arteries of the 

 tentacles are the only parts that are contractile. The dorsal vessel 

 appears to be filled from lacunae in the enteric walls, and its lumen 

 appears to be a continuation of the cavity within the entero-fibrous 

 layer. 



The segmental organs are found in all the fully developed seg- 

 ments, placed in the lateral line, without the peritoneum. They com- 

 mence by a narrow infundibulum, armed with a long flagellum ; the wall 

 of the succeeding portion is filled with granules and provided with 

 delicate cilia ; the external orifice is in the lateral line, and pierces 

 the ectoderm. 



Protodrilus, like some species of Polygordius, is hermaphrodite ; 

 the ovaries, which consist of very small cells, are found in the seven 

 most anterior trunk-segments ; behind these the testes are developed. 

 In some species of Polygordius the ovaries as well as the testes are 

 developed in the more posterior segments ; this would seem to indi- 

 cate that primitively all the segments were hermaphrodite. 



The author concludes by remarking on the extreme simplicity 

 which may be exhibited within the limits of the Annelid type. 



Enchytrseus cavicola.* — This is a new species of a blind worm, 

 described by Dr. G. Joseph, and discovered in a grotto. The greyish- 

 white body has a transjiarent integument ; the ccelom is always in 

 communication with the exterior by means of a porus cepliaUcus, which 

 is placed between the cephalic and oral lobes ; the dorsal vessel has a 

 definite wall only in the anterior third of the body ; the blood was 

 reddish in colour. The oesophageal ganglionic swelling is reniform in 

 shape, and gives an indication of a commissure by a shallow grove. 

 The orifices of the oviducts are transverse clefts, placed between the 



* ' Zool. Aijzeig.,' ill. (IS80) p. 358. 



