. Discovery reports. Discovery (Ship); Scientific expeditions; Ocean; Antarctica; Falkland Islands. NEMERTEANS 23'. Genus Cerebratulus, Renier Cerebratulus aerugatus, Burger, 1892 (Plate XV, fig. 5; Figs. 7, 8). The anterior end of a Lineid worm was found in a kelp root torn from the rocks be- tween the whaling stations. The length was 5-5 cm., the breadth of the head about i-omm. A distinct shallow groove was noticed in the mid-dorsal line of the head. The diverticula of the gut were very regularly placed opposite one another. Form and colour in life. The body is soft and a little flattened.
. Discovery reports. Discovery (Ship); Scientific expeditions; Ocean; Antarctica; Falkland Islands. NEMERTEANS 23'. Genus Cerebratulus, Renier Cerebratulus aerugatus, Burger, 1892 (Plate XV, fig. 5; Figs. 7, 8). The anterior end of a Lineid worm was found in a kelp root torn from the rocks be- tween the whaling stations. The length was 5-5 cm., the breadth of the head about i-omm. A distinct shallow groove was noticed in the mid-dorsal line of the head. The diverticula of the gut were very regularly placed opposite one another. Form and colour in life. The body is soft and a little flattened. The head is lance- shaped, flat and broader at the level of the ends of the cephalic slits than the succeeding part of the body. The cephalic slits are very long. There are no eyes. The mouth is small, placed mid-ventrally behind the ends of the cephalic slits. The body is reddish brown towards the anterior end, fading to yellow posteriorly. The greater part of the head is white. A vague red patch is visible dorsally and ventrally where the body colour fades at the back of the head. In spirit the colour is brownish. Internal structure. The tip of the snout was unfortunately missed in sectioning so that the frontal organs are not known. The head glands are thin and scattered. They extend back as far as the brain. No trace of eyes could be seen. In the stomach region the epithelium is about as thick as that part of the longitudinal muscles into which the cuticular glands penetrate. The outer longitudinal muscle layer is from three to four times as thick as the circular layer, while the inner longitudinal layer is thinner than the circular. There is no diagonal layer. The circular muscles of the rhynchocoel are about as thick as those of the circular layer of the body (Fig- 7)- There is a vascular loop in the head. Posterior to the brain the dorsal vessel protrudes into the rhynchocoel and a number of blood spaces of varying size surround the stomach (Fig. 7). The excretory system
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Keywords: ., bookcentury1900, booksubjectocean, booksubjectscientificexpediti
