62 
Proceedings of the Royal Society of Edinburgh. [Sess. 
IX. — Observations on the Structure and Affinities of Branchio- 
maldane uincenti Langerhans. By J. H. Ashworth, D.Sc., 
Lecturer in Invertebrate Zoology, University of Edinburgh. (With 
One Plate.) 
(MS. received January 22, 1912. Head January 22, 1912.) 
The genus Branchiomaldane, represented by a single species vincenti, was 
founded by Langerhans * to contain certain small Polychsetes, which he 
discovered living in sand-covered tubes, among algae, on the northern shore of 
Teneriffe. Professor Mesnil j- has since found specimens, inhabiting mucous 
tubes situated on the lower side of the calcareous alga Lithothamnion, in 
rock-pools at St Martin, near Cape la Hague, and has given an account of 
some of the structural features of these worms, which he showed to be adult 
and hermaphrodite. Professor Fauvel J considered B. vincenti to be a 
dwarf Arenicola , arrested in development ; he therefore merged Branchio- 
maldane with Arenicola , and designated the worm Arenicola vincenti. 
The writer has investigated the anatomy of several specimens of this worm, 
kindly sent to him by Professor Mesnil, and has concluded that the genus 
Branchiomaldane should be retained ; the original name of the worm — 
B. vincenti — is therefore employed in the following account. § 
The form of B. vincenti is shown in the Plate, fig. 1, which represents 
a specimen 8 mm. long. Average specimens are about 8 to 11 mm. long, 
and *3 to ’5 mm. in diameter at their widest part ; the largest recorded 
specimen is 20 mm. long. 
The prostomium is bluntly conical (fig. 2), or sometimes more rounded 
or ovoid, and overhangs the mouth. It bears groups of eyes, the number 
and disposition of which vary a little in different specimens. The eyes are 
usually arranged so as to form, on each side, an antero-lateral group, 
generally situated well down the side of the prostomium, and a dorsal 
group, near the hind margin of the prostomium. 
The peristomium, which is achsetous, is divided from the prostomium 
by a shallow groove. There is not a pocket-like, nuchal invagination of 
* Nova Acta K. Leop. -Carol. ATcad ., Bd. xlii. (1881), p. 116 ; tab. v., fig. 21. 
t Bull. Sci. France Belg., T. xxx. (1897), p. 156 ; T. xxxii. (1899), p. 323 ; Zool. Anz ., 
Bd. xxi. (1898), p. 635. 
\ Bull. Sci. France Belg ., T. xxxii. (1899), p. 313 ; Mem. Soc. Nation. Sci. Nat. Math. 
Cherbourg , T. xxxi. (1899), p. 165. 
§ The expenses incurred during this research have been defrayed by a grant from the 
Earl of Moray Endowment of the University of Edinburgh. 
