J 64 



DISCOVERY REPORTS 



proboscis pore is just ventral to the tip of the snout. The colour is blue-green, yellow- 

 green, pale buff or light brown on the back, while the underside is always pale buff. The 

 colour is deepest in individual worms on the hump caused by the proboscis. Occasionally 

 a reddish tinge marks the position of the ganglia and a narrow whitish stripe at the margin 

 of the body anteriorly the lateral glands. 



Form and colour of preserved specimens. After anaesthetization in chloral hydrate very 

 little contraction appears to take place on fixing. The green colour is retained in spirit 

 specimens for many months. The body does not change in shape but contraction causes 

 two grooves to appear, one near the tip of the head, the other a little farther back. When 

 only slightly marked these grooves take the form of two pairs of short lateral vertical 

 furrows. Two irregular groups of very small eyespots — up to sixty — can be seen when 

 the head has been cleared in anilin oil. The eversible part of the proboscis is apple green 

 in colour. 



The anatomy of this species has been described by Hubrecht (1887) and Burger 

 (1904 a, 1907). Variations occur in the following details. The eyespots, though always 

 very small, vary considerably in number, 

 and the pigment granules which they con- 

 tain are of a deep green-blue colour. 



The lateral glands (very strongly de- 

 veloped cerebral subepithelial gland cells) 

 stain deeply with haematoxylin ; the head 

 glands less deeply. The number of nerves 

 in the proboscis may be from eleven to six- 

 teen though the usual number is fourteen. 

 The base of the main stylet may be brown 

 or green and there is a belt of brown gland 

 cells round the armature. The base of the 

 main stylet is less than twice as long as the 

 stylet itself. The brain and cerebral organs 

 are shown in Fig. 39. As noted by Burger 

 (1907 (1912), p. 173) the dorsal ganglia lie 

 laterally rather than dorsally to the ventral. 

 They are, as it were, pressed forwards and 

 outwards so that they are in almost the same 

 plane as the ventral ganglia. In consequence 

 the dorsal commissure is very long. The 

 double twist in the lateral nerves is probably 

 the result of contraction. The cerebral organs, consisting of a narrow canal ensheathed 

 by eosinophile tissue on each side, extend a short way beneath the dorsal ganglia but 

 do not penetrate them. 



Fig. 39. Amphipoms moseleyi, Hubrecht. Diagram 

 of the anterior end of the body showing the brain, 

 cerebral organs, cerebral subepithelial glands and 

 the position of the opening of the rhynchodaeum 

 and the opening of the oesophagus into it. 



