Discovery reports (1934) Discovery reports discoveryreports09inst Year: 1934 NEMERTEANS 233 numerous in the epithelium. Farther back on the body many of the subepithelial cells stain with eosin. The rhynchocoel is long, but the proboscis is attached in the first half of the body. Two vascular lacunae close to the rhynchodaeum can be traced back to the anterior insertion of the proboscis. They reappear as a median lacuna ventral to the rhynchocoel; and from this lacuna arises the dorsal vessel and a dorsal lacuna which later divides into two lateral lacunae in which lie the cerebral organs. P
Discovery reports (1934) Discovery reports discoveryreports09inst Year: 1934 NEMERTEANS 233 numerous in the epithelium. Farther back on the body many of the subepithelial cells stain with eosin. The rhynchocoel is long, but the proboscis is attached in the first half of the body. Two vascular lacunae close to the rhynchodaeum can be traced back to the anterior insertion of the proboscis. They reappear as a median lacuna ventral to the rhynchocoel; and from this lacuna arises the dorsal vessel and a dorsal lacuna which later divides into two lateral lacunae in which lie the cerebral organs. Posterior to the brain the vascular system has not been traced. The brain is very large (Fig. 10). There is a strong upper branch to the dorsal ganglion posteriorly. This upper horn disappears before the lower, which is invested with the cerebral organ and forms the posterior lobe of the brain. A dorsal nerve arises from the dorsal commissure. On the intrusion of the mouth the ventral ganglia separate and from this point they may be called the lateral nerves. Previous to this the ganglia are close together and directly beneath the dorsal ganglia. They curve outwards sharply to take up their lateral positions. A pair of nerves is given off before the separation for the innervation of the pharyngeal muscles. The differences between these specimens and the worms described by Mcintosh (1873) are so slight that I have no hesita- v 'J/ .... _, „, Fig. 10. Cerebratulus fuscus, Mcintosh. Irans- tion in identifying them as C. fuscus. 1 he yerse section of the body at the extreme anterior pigmentation is more distinct, but worms limit of the mouth, of the same species even more distinctly marked have been described by Joubin (1894). Burger (1895) gives the body form as characteristic—the tail being very wide. Evidently this is a variable character for Mcintosh's description is 'slightly tapered towards either extremity'. The internal structure bears out the identification, although I
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