REPORT ON THE MARSENIAD^E. 23 



2. Marseniopsis murrayi, n. sp. (Plate I. figs. 28-38). 

 Habitat. — Southern Ocean, off Marion Island. 



Only a single (male) specimen of this species was dredged on the 26th December, 

 1873, from a depth of 50 to 75 fathoms, near Marion Island. 



The specimen, as preserved in alcohol, had a length of 18 mm., a maximum breadth 

 and height of 15 and 12 - 5 mm. respectively. The foot was 15 mm. long, and had an 

 anterior breadth of 6 "5 mm. ; the breadth of the mantle border was 4 mm., the length 

 of the penis 7, of the tentacles 4, and of the tail 8 mm. The general colour was 

 (greyish) reddish brown, the lower side of the mantle border and the neck portion 

 were yellowish white. 



The dorsal surface was much arched, arid covered with depressed, rounded tubercles; 

 the border of the mantle was thick and very like that of the Onchidiopsides ; the respira- 

 tory canal was bent upwards and lay in an almost median position ; the head and 

 tentacles were as usual. The inside of the mantle, adjacent to the shell, had a reddish 

 white colour. The shell measured 13"5 mm. in length, 10'5 and 8 mm. in maximum 

 breadth and height respectively. It was very hard and brittle, and quite thin. 1 



After removing the shell, the viscera were seen in the ordinary arrangement ; pos- 

 teriorly, the large apparently granular, faintly reddish-yellow testis, with a narrow, dark 

 brownish-grey border arising from the liver. In front of the testis lay the bright reddish- 

 grey foliated gland, shining through which the somewhat darker intestine was seen. 

 Before the former there lay a broad, glistening white band, consisting of distinctly sepa- 

 rated portions, arranged longitudinally, and resulting from the products of the kidney and 

 of the foliated gland. At the left corner of this band, the bright reddish-brown kidney 

 was situated, and in front of the foliated gland the branchia and the olfactory organ could 

 be faintly seen shining through, while the anterior end of these two organs projected some- 

 what markedly from the branchial cleft. The small facettes of the shell-muscles lay far 

 forward. 



The viscera of the lower body-cavity could be but indistinctly seen shining through 

 the floor of the branchial cavity ; the vas deferens was distinctly visible towards the root 

 of the penis. 



The central nervous system was exactly as in the above-described species. The otocysts 

 were seen as white calcareous points, lying however more externally than in the above. 



The bidbus pharyngeus was as before, but smaller ; the lip plates exhibited the already 



described structure (fig. 28), and measured 075 mm. in length. The tongue was furnished 



with 24 rows of tooth plates, of which the first 5 were more or less defective ; further 



back there were 40 developed and 8 younger rows, making a total of 72. The median 



plates had almost constantly 6 to 8 denticles on each side of the rather long pointed 



1 In the specimen examined the mantle had been opened and an attempt made to take out the shell, 

 which had thus been broken into several pieces ; these still remained, however, in their original place. 



