398 — Prof. Grube on the Annelid Family Maldaniea. 
above-mentioned lateral furrows at the posterior extremity are 
wanting, and a distinct posterior surface is developed upon it. 
As regards Maldane, in which the terminal segment shows 
so close a resemblance to the buccal segment of Clymene, 
Malmgren has refuted the author’s erroneous conception, 
according to which the former was the buccal segment, 
and the uncini stood above the sete, and has. established 
the correct generic character. The terminal segment has its 
apical surface inclined downwards and forwards, or nearly 
vertical and circular; the anus is situated above this; and the 
preceding naked segment, which, like the setigerous seg- 
ments, is biannulate, shows no indications of lateral or ventral 
cushions. ‘The vertical plate possesses a distinct margin, as 
in Clymene; and the setee are partly bordered, partly finely 
denticulated. 
Of the three species belonging to the genus, M. biceps (Cly- 
mene biceps, Sars) and Cl. Sarsii, Malmer., are Scandinavian 
and Arctic, and WM. glebifex, Gr., from the Mediterranean. 
The genus Petaloproctus, Quatref., established upon a single 
species, is distinguished from Maldane partly by the want of 
a vertical plate, and by its much abbreviated, hemispherically 
inflated buccal segment, upon the anterior half of which, how- 
ever, the median stripe representing the cephalic lobe is very 
distinctly marked in the form of a keel, and partly by a pos- 
teriorly inclined dorsal plate of the terminal segment including 
the anus itself. 
This species is P. terricola, Quatref., from St. Sebastian, 
described as with 24 segments, of which 4 belong to the 
anterior, 14 to the median, and 6 to the posterior region of the 
body ; the last two, however, are not readily distinguishable, 
as, according to Quatrefages, their segments bear sete and 
uncini. The author believes he has met with the same animal 
at St. Vaast, but counts in it only 22 setigerous segments: 
the buccal and terminal segments are, as in all cases, destitute 
of bristles; and the latter does not appear to be preceded by ° 
any non-setigerous segments. If there be no error in Quatre- 
fage’s statement of the number of setigerous segments, his 
animal would possess in all 26 segments, as the buccal and 
terminal segments in the Maldaniea are never furnished with 
sete. Moreover it is to be remarked that, in the Petalo- 
proctus from St. Vaast, the cushions for the uncini of the 
seventeenth and five following segments extend even upon 
the back, where they close like a ring, and that this dorsal 
part of the segment is produced backward into a broad, thick 
point. The caudal extremity of Clymene spathulata so ex- 
actly corresponds with this description, that it probably 
