XV.-—On Branchiura sowerbyi Beddard, and on a new species of Limnodrilus with 
distinctive characters. By J. Stephenson, M.B., D.Sc. (Lond.), Major, Indian 
Medical Service ; Professor of Biology, Government College, Lahore. Commumn- 
cated by Professor Ewart. (With Two Plates.) 
(MS. received October 25,1911. Read December 4, 1911. Issued separately May 28, 1912.) 
On a recent occasion, looking into a small shallow pool near Lahore, I saw here and 
there on its bottom a reddish appearance, which a closer examination showed to be due 
to innumerable worms, implanted by one extremity in the mud, and waving their free 
ends in the water. These were the Limnodrilus described below. A quantity of the 
mud taken for further examination yielded, though in very much smaller numbers, 
three other Oligochetes, viz. Branchiura sowerbyt, Lahoria hortensis, and a species 
of Dero. 
Branchwura sowerbyi: was originally described by Brpparp (2) from specimens 
found in mud from the “ Victoria regia tank” in the Royal Botanical Society’s Gardens, 
Regent's Park. Its most distinctive feature is the possession of a double series of 
finger-like gills on the posterior part of the body, one row being placed along the mid- 
dorsal, the other along the mid-ventral line. Lahoria hortensis was originally described 
by me (9) from a small pond in the Lawrence Gardens at Lahore; it is not common; 
and, not having met with it for two years, I had begun to think that it had disappeared. 
It belongs to the Naidide; like Branchiwra sowerbyr, it possesses two rows of gill- 
processes, but these are either limited to, or best developed on, the anterior part of the 
body, and are dorso-lateral in position. Dero is well known as a Naid which possesses 
a small number of gill-processes at the posterior end of the body round the anus. 
Tamnodrilus is remarkable in possessing a cutaneous capillary plexus in the posterior 
part of its body,—better marked in this, apparently, than in most of the other species 
of the genus ; and this feature, and the constant waving movements of its tail, have 
doubtless a respiratory significance. 
There were here, therefore, living together, four genera of Oligocheetes, with peculiar 
and specialised respiratory arrangements; and, by a curious coincidence, three of them 
were among the very few known Oligochetes which possess gills. 
The coincidence," however, does not end here. Brpparp, in his paper on Branchiura 
sowerbyi, relates that the mud which provided him with this form also contained three 
or four examples of Chetobranchus semperi, a gilled Naid previously described from 
Madras by Bourne (4). Branchiwra sowerby: has been recorded twice since then 
(1892) (v. inf.), but Chetobranchus has apparently not been seen again. Lahoria, 
however, resembles Chetobranchus very closely in many ways,* the chief difference 
* MICHAELSEN (7) indeed includes it in the genus Branchiodrilus, Mchlsn. (=Chetobranchus, Bourne). I have 
discussed the question in my original paper (9) ; the point depends on the value to be attached to “cephalisation,” 
TRANS. ROY. SOC. EDIN., VOL. XLVIII. PART II. (NO. 15). 44 
