828 mb. b. c. pi'N.vETT ok [Nov. 20, 



procured. Width about 2-5 mm. The head-slits are very long, 

 extending over 5 mm. The posterior 3 mm., however, are very 

 shallow. The mouth commences at about the termination of the 

 deep portion of the head-slits and is about 3 mm. in length. After 

 preservation the colour was dark olive-brown. Starting from 

 about "5 mm. from the tip of the snout, a paler dorsal band about 

 1 mm. in breadth reached backwards. 



The epithelium contains a number of large granular unicellular 

 glands in its deeper portion. Beneath the thin basement-membrane 

 is a layer of longitudinal muscle- fibrils in the cutis, and underneath 

 these again are the cutis-glands and the connective-tissue layer of 

 the cutis. Dorso-laterally for a small portion of the circumference, 

 as seen in transverse section, the cutis is modified on each side by 

 the presence of an enormous quantity of what appear to be small 

 rhabdites (fig. 4, rh.). They take a very vivid colour with picric 

 acid, and may easily be traced through the cutis-muscles (rale), the 

 basement-membrane, and the epithelium. 



The muscle-layers show no special features. There is no diagonal 

 layer. 



In the vascular system there is a well-marked head-loop. It was 

 not possible to fix definitely the point of exit of the dorsal vessel, 

 as the fragment cut only just included the excretory system. At 

 this level the vessel still ran in the sheath. 



The proboscis was lacking. 



The proboscis-sheath shows the usual inner longitudinal and outer 

 circular muscle-layers. 



The excretory system commences at the posterior limit of the 

 cerebral organ (fig. 5). It lies wholly dorsal to the level of the 

 side stems. There is a single duct on each side near its middle 

 portion. 



In the nervous system the median dorsal nerve is well marked. 

 The dorsal commissure in the brain is very posteriorly situated, 

 not being given off until after the separation of the dorsal from the 

 ventral ganglia. Xeurochord-cells are present at the level of the 

 ventral commissure. The dorsal lobe of the dorsal ganglion is large. 

 The brain as a whole is much flattened, as, indeed, is the whole of 

 the fragment by which this species is at present represented. 



The cerebral organ is elliptical in shape, being flattened dorso- 

 ventrally. Gland-cells are found above and below (fig. 2 c-e). 

 A portion open into the ciliated canal before it joins the dorsal 

 ganglion (fig. 2 a). 



The frontal organ is well marked. 



Eyes are probably absent. 



The head-glands are very short and soon become fused with the 

 cutis-glands. 



This species bears some resemblance to that described by Burger 

 (1) under the name of Cerebratulus spadix, but seems to be distin- 

 guished from it by the vascular head-loop and by the fact that the 

 mouth commences before the termination of the cerebral organs. 

 The curious agglomeration of rhabdites also seems peculiar. 



