Videnskabelige meddelelser

booksnow2.scholarsportal.info

Videnskabelige meddelelser

these no male is found ;

most

202

of them are young individuals

but a great deal are mature females containing shell-eggs in the

uterus.

The Danish specimens agree well with the description of de

Man so that I have not much to add. The ventral gland and its

long excretory duet is much like that in Enchelidiiim tenuicolle

Eberth; fig. 1, PI. XII shows this. Like in Enchelidium the ex-

cretory duet is protoplasmatic in structure and a part of the secern-

ating cell itseif; also in Symplocostoma is found an ampulla near

the excretory pore (PI. XII, fig. 3), but it is not easy to ascertain

whether the tube issuing from the ampulla is a formation origin-

ating from the cuticle as is the case in Enchelidium. In Symplo-

costoma are seen some streaks in the ampulla which could argue

a valvular apparatus but it is impossible to see where the proto-

plasmatic structure ceases and the chitinized commences.

The caudal gland is — as supposed by de Man already in

1888 -— found a great distance from the tail; three distinct gland-

ular cells are seen (PI. XIII, fig. 6), and in respect to their efferent

duets they seem to behave as the ventral gland. Each of these

cells has its own duet of protoplasmatic structure which is a

part of the protoplasma of the secernating cell itseif. The three

duets may be foUowed to the tip of the tail where they open. De

Man writes: „La glande caudale semble étre située å quelque

distance en avant de l'anus et se compose, å ce qu'il parait de

deux OU trois grandes cellules ovalaires." On preparations stained

with carm-alum or treated with osmic acid I have been able to

ascertain the correctness of the supposition of de Man.

Eurystoma Marion.

Eurystoma filiforme de Man.

1888. Eurystoma filiforme de Man, Sur quelques Némat. p. 26.

1914. — Southern, Clare Island Survey. p. 41.

1916. — Steiner, BarentseeNemat. p. 602.

Little Belt; off Snoghøj, c. 30 m.

Only two specimens were taken, a male and a female ; they

are both typical and agree well with the description of de Man.

Southern remarks that the tip of the spicules „has several teeth

on the posterior edge". I find in my specimens the tip somewha^

II

More magazines by this user
Similar magazines