Videnskabelige meddelelser

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Videnskabelige meddelelser

179

The movement here described is not due to an evagination of

the foremost part of the body; the rods are protracted and retracted

by a special system of muscles; the lateral organs do not change

their place during the process.

Unfortunately I have not had an occasion to study the move-

ments of the rods on living specimens and consequently I am not

able to State anything about rapidity or energy with which the

named movements are performed. In my preparations are found

specimens with retracted rods as well as specimens with the rods

protracted.

The feature here mentioned recalls that of the genus Iro-

nus about which de Man in 1884 writes that it differs from the

other freeliving Nematodes „durch die eigentiimliche Bildung des

Kopfes und der Mundhohle". Later on the same author has de-

scribed a related genus from salt water, Thalassironiis. In Tri-

gonolainms I suppose we have a parallel to the named genera,

provided with protractile „jaws". I propose the name „jaw" for

these organs, that is to say the same designation which I apply

ater on in this paper for the mo vable jaws in the genera Eno-

phis and Enoplolaimus. The well-known transverse striation of the

æsophagus reaches in the species under consideration only to the

level of the bottom of the buccal cavity ; this latter is surrounded

by another very complicated muscular apparatus, mainly consisting

of pro- and retractors for the jaws and their supporting bodies.

The lateral organ is large, loop-shaped, of about the same

aspect as is known in Aræolnimus microphthalmiis de Man, in

ertain species of the genus Dipellis Cobb and in the new genus

liathylaimus, established in this paper. In the species in question

t is situated at the level of the foremost part of the buccal cav-

ty which contains the jaws.

The æsophagus is short and increases gradually but slightly

n its posterior half; no bulb is formed. The nerve-ring is very

ndistinct, I have not been able to ascertain its position in any of

he specimens.

The intestine is crowded with minute granules.

Somewhat behind the base of the æsophagus is situated the

entral gland ; the excretory pore is not seen. Besides the ventral

land some few unicellular glands with short, chitinized, tubular

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