. Discovery reports. Discovery (Ship); Scientific expeditions; Ocean; Antarctica; Falkland Islands. A - B Fig. 15. Zygonemertes capensis, A, transverse section across the head at the level of the ventral com- missure ; B, transverse section across the body at about half its length to show the opening of the genital sacs; C, transverse section 0-025 mm- from tip of tail. In some specimens the protruded proboscis is nearly as long as the body, in others it is about a quarter of the body length. These differences are probably due to different states of contraction and extension of the probo
. Discovery reports. Discovery (Ship); Scientific expeditions; Ocean; Antarctica; Falkland Islands. A - B Fig. 15. Zygonemertes capensis, A, transverse section across the head at the level of the ventral com- missure ; B, transverse section across the body at about half its length to show the opening of the genital sacs; C, transverse section 0-025 mm- from tip of tail. In some specimens the protruded proboscis is nearly as long as the body, in others it is about a quarter of the body length. These differences are probably due to different states of contraction and extension of the proboscis and body on fixing. There are thir- teen nerves. That part of the proboscis posterior to the armature is shorter than the anterior part and is inserted in the rhynchocoel at about one-third or half the length of the body. The rhynchocoel extends to the posterior end of the body (Figs. 15B and C). The armature (Fig. 16) consists of a main stylet on a base of unusual length, and two accessory reservoirs each with two, three or four stylets. Often one of the accessory stylets is incomplete. The base of the main stylet varies between two and a half to five times the length of the stylet. Measurements of three armatures from green and brown forms are given below: o-i33 0-130 Main stylet (mm.) ... 0-115 °-I56 Base of stylet (mm.) ... 0-518 0-714 Accessory stylet (mm.) 0-164 0-182 In the uncoloured forms the difference in length between base and main stylet is not so marked: Main stylet (mm.) 0-078 0-050 Base of stylet (mm.) ... 0-117 0-084. Fig. 16. Zygonemertes capensis, Arma- ture of the green form (cleared in anilin oil).. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Institute of Oceanographic Sciences (Great Britain); National Institute of Oceanography of Great Britain; Great Britain. Colonial O
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