1900.] WEMERTEA"N T S FROM TORRES STRAITS. 827 



in length and reached rather over the mouth which was 2 mm. long. 

 Colour in life a uniform brown. 



The epithelium contains in its outer part a number of granular 

 unicellular gland-cells (fig. 3). It rests on a well-developed base- 

 ment-membrane (5m.), beneath which is the outer longitudinal 

 muscle-layer of the body-wall. Squeezed in between the muscles 

 are the somewhat scanty cutis-glands (cgl.). There is no connective- 

 tissue layer (Bindgewebsschicht). 



The muscular system presents no features of special interest. 

 There is no diagonal muscle-layer. 



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

 The dorsal blood-vessel quits the proboscis-sheath at the level of 

 the posterior termination of the excretory system, and at this same 

 level the oesophageal lacunae cease, becoming confluent with the 

 two lateral blood-vessels, which at this level are very large. 

 The proboscis is lacking. 



The proboscis-sheath contains the usual outer longitudinal and 

 inner circular muscle-layers. 



The alimentary canal possesses a small ventral gutter. 

 The generative sacs contained ova. 



The excretory system commences some little way behind the 

 mouth (fig. 6). On both sides there is a duct opening to the 

 exterior near its posterior end. On the left side there is an 

 additional duct at the anterior end. The system lies for its whole 

 extent dorsal to the level of the side stems. 



In the nervous system the median dorsal nerve is scarcely differ- 

 entiated from the nervous sheath surrounding the circular muscle- 

 layer. Anteriorly well-marked head-nerves are given off the dorsal 

 ganglion. The dorsal commissure is stronger than is usual in the 

 group, and is given off slightly behind the level of the ventral one. 

 In both the dorsal and ventral ganglia and in the side stems the 

 central fibrous core is unusually large in comparison with the 

 thickness of the ganglion-cell layer. Neurochord-cells occur in 

 the brain at the level of the ventral commissure. The dorsal lobe 

 of the dorsal ganglion is large and reaches back some way (fig. 1 

 a-c, ddy.). 



The cerebral organ is rounded in form and is partly covered by 

 gland-cells both above and below. 



The head-slits are deep, reaching nearly to the brain. Even 

 after the ciliated canal has been given off, they remain deep for a 

 considerable distance (fig. 1 a-d, hs., & fig. 6, hs.). 



Eyes are probably represented by small structures lying dorsal 



to the head-slits in the snout, though in the absence of a well- 



marked pigmentary layer (which may have been extracted by the 



long sojourn in spirit) it is impossible to be certain. 



The frontal organ is well marked. 



The head-glands are scanty and soon fuse with the cutis-glands. 



Cerebratxjll t s queexslaxmci's, n. sp. (Plate LIV. figs. 2 a-e, 

 4, & 5.) 



Fragments of the anterior portion of a single specimen were 



