324 
MM. Koren and Danielssen on some 
of an oesophageal ring with one cerebral and two pedal (infra- 
cesophageal, Tullb.) ganglia. 
Family I. Solenopodidae, K. & D. 
(Neomemadce, Ihering.) 
Along the ventral surface a furrow, within which the long 
narrow foot is concealed. Branchiae filiform. 
Genus 1. Solenopus, M. Sars, 1868. 
Vermiculm, Dalyell, 1853. 
Neomenia, T. Tull berg, 1875. 
Body cylindrical, with filiform branchiae at its posterior 
truncated extremity. Above the branchial cavity in the pos¬ 
terior margin of the mantle a genital pore, and in the bottom 
of the branchial cavity an anal orifice. Buccal mass thick, 
muscular, capable of beiug completely covered by the mantle, 
which is covered all over with diversely formed calcareous 
spicules. Along the ventral surface a furrow, in which the 
foot is concealed. 
1. Solenopus nitidulus, M. Sars. 
Neornenia carinata , T. Tullb. 
The body is nearly round, but a little flattened on the ven¬ 
tral surface, 30 millims. long, 10 millims. broad. Back con¬ 
vex, furnished with a keel. The ventral surface has a furrow, 
which is formed by the lateral margins of the mantle, and 
commences 6 millims. from the anterior extremity of the 
animal, and extends towards the posterior extremity, termi¬ 
nating 8 millims. from the latter. In the bottom of this fur¬ 
row lies the foot, the anterior part of which is thick, round, 
3 millims. in breadth, and becomes narrower and narrower as 
it approaches the animal’s posterior extremity. The lateral 
margins of the mantle can shut close together ; and then only 
a fine stria is visible; whilst when they separate from each 
other the furrow becomes tolerably broad, and then the foot 
conies into view. In the anterior part, towards the ventral 
surface, the mantle forms a longitudinal fissure, which can 
expand and contract; within this there is a cavity, surrounded 
by a fold of skin, which is broader towards the sides, nar¬ 
rower anteriorly and posteriorly. In the bottom of the cavity, 
somewhat posteriorly, appears the round buccal aperture. At 
the posterior extremity, likewise towards the ventral surface, 
there is also a fissure in the mantle, which can expand and 
