Videnskabelige meddelelser

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Videnskabelige meddelelser

199

shows some Protozoan parasites (PI. XV, fig. 4) of an aspect re-

minding one of small planarians: The front end(?) is truncate, the

hindpart tapers quickly but is rounded. The length makes 66 /(,

the width 14 //. The ectoplasm is rather hyaline, the endoplasm

is strongly vacuolated; no nucleus is seen. Six of these relatively

large parasites are found in the intestine at the level of the vulva,

one is seen in the hindmost part of the intestine just before the

rectum. All the parasites are arranged with their front ends (?)

pointing caudad.

I suppose they are gregarines of the group Acephalinæ.

Cyatholaimus microdon n. sp.

PI. XI. lig 10 : PI. XV. fig. G.

Limfjord; Holme Flak, shallow water.

This species is easily distinguished from the hitherto described

Cyatholaimi by its relatively long tail, the little, inconspicuous

tooth and the extremely small lateral organ, situated behind the

buccal cavity.

Only one specimen was taken, a female of the length of 1,2

mm. In the front end the body tapers gradually, the head is rounded

(PI. XI, fig. 10). The tail is of the usual conical form but relatively

long (PI. XV, fig. 6).

The annulation of the cuticle is very fine and the system of

points more delicate than in any other Cyatholaimus which I have

had occasion to examine. With the aid of Zeiss Apochr. 2 mm it

was just possible to see the transverse rows of points where these

were most prominent. The larger, chitinized bases of papillæ, so

common in other species of this genus, seem to be lacking here; at

any rate I have not succeeded in finding any.

The papillæ of the head are very indistinct; the cephalic brist-

les are short and rather slender. The buccal cavity is of usual

shape, the tooth, as remarked, relatively small.

Lateral organ is spiral-shaped ; it is small and consists of little

more than two loops; the spiral line of the outmost loop does not

end free but bends inwards to the foregoing loop (PI. XI, fig. 10),

a feature also known in C. ocellatiis. Some distance behind the

lateral organ are found two eyes each consisting of a cup-shaped

pigment heap, but no lens is seen. The distance of the eyes to the

front end makes 72 //. The lateral organ is situated about in the

middle between the front end and the eyes.