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DISCOVERY REPORTS 



wrinkled, the small deep wrinkles giving almost a matted appearance. Down the centre 

 of the back is a raised ridge with a longi- 

 tudinal groove on each side of it. Ventrally 

 the wrinkling is mainly in the form of longi- 

 tudinal furrows of which the median ones are 

 the deepest. There is a furrow at the back of 

 the head and the mouth is just behind this 

 in the middle line (Fig. 19). 



Internal structure. There appear to be 

 frontal organs as shallow pits at the corners 

 of a depression at the tip of the head. Head 

 glands are not evident in the early sections, 

 but about midway between the proboscis 

 pore and the brain they appear, stained 

 palely with haematoxylin, scattered through 

 the musculature, especially ventrolaterally. 

 Dorsally they are thin, also mid-ventrally, 

 and they disappear altogether before the 

 brain. 



The position of the brain, cerebral organs, 

 proboscis pore and mouth can be seen in 

 the graphic reconstruction (Fig. 20). The 

 proboscis is thin and also its sheath. The 

 mouth is small and rounded. The epithelial 

 layer is thin and the cutis deep. The 

 gelatinous tissue developed between the 

 bundles of the outer longitudinal muscle 

 layer (Baylis) is extraordinarily well-marked 

 in the larger specimens and is responsible for 

 the unusual degree of wrinkling of the skin. 



Fig. 20. Baseodiscus antarcticus, Baylis. Diagram 

 of the organs at the anterior end of the body and 

 head, co, cerebral organ; dg, dorsal ganglion; 

 fo, frontal organ; hg, head gland; m, mouth; 

 wr, deep wrinkles on the dorsal surface of the 

 head. (From a graphic reconstruction.) 



Genus Parapolia, Coe 



Parapolia grytvikenensis, n.sp. (Plate XVI, fig. 14; Figs. 21, 22). 



One specimen (N 43) was collected at St. 123 from 230-250 m. The contracted length 

 in life was 4 cm., breadth 0-27 cm. 



Form and colour in life. The body is stout and cylindrical in the passive and con- 

 tracted condition in which the single specimen was found. The head is acutely pointed, 

 flattened, and is separated from the body by a slight "neck". The tail is blunt. The 

 mouth can be seen as a small longitudinal slit some way back from the tip of the head. 

 Neither cephalic slits nor eyespots can be seen. The colour is pinkish brown, darkening 

 towards the tail. 



