424 • Proceedings of the Roijal Physical Society. 



Kadstock. 3a. Vertical section of one of the cushions {a indicates position 

 of leaf-scar, h its supporting cushion), 2>h. Leaf-scar, enlarged 1^ diameters, 

 to show the vascular cicatricules, the central of which is composed of 

 two confluent dots. 4. Figure from plaster cast of an impression in the 

 collection of Mr McMurtrie. 4a. Vertical section of one of the cushious. 

 5. Four cushions with their associated leaf-scars, from a specimen in the 

 author's collection. Communicated by Mr J. McMurtrie. The part marked 

 a shows the decorticated condition. 5a. Vertical section of one of the 

 cushions. 



Fig. 6. Lcpidodendron Pcachii, Kidston, n. sp. From the Brickworks, 

 Falkirk, Stirlingshire (nat. size). Original in the collection of Mr C. "W. 

 Peach. Qa. Leaf-scar, enlarged 2 diameters. 6^. Leaf-scar, shown in profile, 

 enlarsjed 2 diameters. 



XXXIV. Note on the Paired Dorsal Vessel of Certain Earlh- 

 loorms. By F. E. Beddard, Esq., M.A., E.Z.S., Prosector 

 to the Zoological Society of London. [Plate XXIL] 



(Read 20th May 1885.) 



In studying the anatomy of several new forms of earth- 

 worms that I have lately received from New Zealand by the 

 kindness of Professor T. J. Parker, I noted the fact that in cer- 

 tain of them the dorsal trunk of the vascular system is repre- 

 sented by two trunks, more or less completely separate from 

 each other. This fact is of some interest, because it is known 

 that the single dorsal vessel of Lumhricus is represented in 

 the embryo by two rudiments, which only subsequently 

 coalesce. This fact we owe to the researches of Kovalevsky ; ^ 

 Vejdovsky has more recently extended the discovery to 

 Crioclrilus, and has published a brief account of his observa- 

 tions in a preliminary note addressed to the Bohemian 

 Academy.^ The two rudiments of what is subsequently to 

 become the unpaired dorsal vessel of the adult Crioclrilus are 

 situated above, and rather to the side of, the intestine ; their 

 position in fact would appear to correspond very closely to 

 the lateral vessels, or intestino-tegumentary trunks as Perrier 

 has termed them, which are found in Lujiibricns and in many 

 other genera of earthworms, but do not seem to be repre- 



1 Mem. d. I'Acad. de St Petersb. 1871. - S. B. Bohm. Acad. 1879. 



