A CONTRIBUTION TO THE ANNELIDA. 53 
A Contribution to our Knowledge of the 
Annelida. 
On some Points in the Structure of Euphrosyne. 
On Certain Young Stages of Magelona and on Clapareéde’s 
unknown Larval Spio. 
By 
Ww. C. McIntosh, 
St. Andrews Marine Laboratory. 
With Plates 6—8. 
On some Points IN THE STRUCTURE OF EUPHROSYNE. 
In the circumstances under which the present paper is con- 
tributed, it is perhaps fitting that a form should be selected 
(viz. Euphrosyne) which first came under my notice by the 
kindness of Professor Ray Lankester, who sent preparations 
procured in Herm in 1865. When an opportunity occurred a 
few years later (1868) of becoming familiar with living exam- 
ples on the same ground, unfortunately time did not permit a 
detailed investigation of internal structure, and accordingly I 
have had to content myself with the examination of rather 
imperfect spirit-specimens. 
While the structure of the genus Spinther, Johnston, has 
been more or Jess fully elucidated by the labours of R, von 
Drasch (‘ Anatomie von Spinther miniaceus,’ Grube, 1885), 
and especially by those of Ludwig von Graff (‘ Die Anneliden- 
gattung Spinther,’ 1887), the present genus, so far as I can 
ascertain, has received attention only from Schmarda! and 
E. Ehlers;? but at the date of their treatises the modern 
1 ¢Wirbellosen Thiere,’ 1, ii, p. 136, pl. 33, figs. 264, 287. 
2 «Die Borstenwiirme,’ i, p. 67, Taf. i and Taf. ii, 1864. 
