A CONTRIBUTION TO THE ANNELIDA. ral 
condition ; but such have never presented at St. Andrews the 
long slender larval papille simultaneously in the same region, 
and which Claparéde shows in his fig. 12. Though the young 
stages of allied members of the Spionide are not yet sufficiently 
known, yet the weight of evidence inclines to the view that the 
Spio-like larve pertain to Magelona, at a stage previous to 
the appearance of the rugose ridges ushering in the thick 
cylindrical papille. An interesting feature is the disparity in 
size between the latter examples without forward growth of the 
snout, and others, fully a third less, with a considerable snout. 
On Cxuaparepre’s Unknown Larvat SPtio. 
The first notice of a form apparently identical with the larval 
Annelid which forms the subject of these remarks is given by 
Maximilian Miller,! who alludes to a fragment of the posterior 
end in connection with his observations on bacillary corpuscles. 
When sojourning at St. Vaast la Hougue, between July and 
September, Claparéde” found not unfrequently an unknown 
larval Annelid (pertaining to a common form) which has also 
occurred in considerable numbers in the bottom-nets at St. 
Andrews from July to October. The same form has been met 
with on the Norwegian coast at Christiansand. 
The youngest stage measures about 0:045 mm., and has 
about twelve bristled segments, besides several without bristles. 
The head is short and is divided into symmetrical lobes. The 
ridge is richly ciliated, and differs from the arrangement in the 
larva of Leucodore. The larger bosses have short cilia and a 
pair of longer ones. The eyes are arranged more or less on a 
trapezoid (the posterior pair more widely separated), and have 
reddish pigment. The mouth lies on the ventral surface be- 
tween two ciliated lobes. Two bands of cilia occur on the 
ventral surface behind the mouth. The first body-segment has 
a larger lateral process than the rest, and bears a long tuft of 
slender bristles, minutely spinose. The succeeding segments 
1 *Qbservat. Anatom. de vermibus quibusdam maritimis,’ 1852, p. 29, 
pl. ii, fig. 29. 
"2 Op. cit., p. 77, Taf. vi, f. J—11. 
