2 
THE VOYAGE OF H.M.S. CHALLENGER. 
was not large. The Challenger collection contains altogether twenty-five species, 
including one deep-sea form of the greatest interest ( Bcithydoris abyssorum). 
The following is a list of the species : — 
1. Phylliroe atlantica, Bergh. 
2. Acura pelagica, Adams. 
3. Acura lanceolata, Bergh. 
4. Fiona marina, Forskal. 
5. Glaucus atlanticus, Forster. 
6. Janolus australis, n. gen. and sp. 
7. Cutlionella abyssicola, n. gen. and sp. 
8. Rizzolia australis, n. sp. 
9. Scyllcea pelagica, Linne. 
10. Bornella excepta, n. sp. 
11. Tritonia challcngcriana, n. sp. 
12. Marionia occidentalis, n. sp. 
13. Ohola paciftca, Bergh. 
14. Euplocamus pacificus, Bergh. 
15. Chromodoris striatella, Bergh. 
1 6. Chromodoris runcinata, Bergh. 
17. Ceratosoma cornigerum, Adams. 
18. Archidoris Jcerguelenensis, n. sp 
19. Archidoris australis, n. sp. 
20. Discodoris morphcea, Bergh. 
21. Platydoris eurychlamys, Bergh. 
22. Thordisa clandestina, n. sp. 
23. Bathydoris abyssorum, n. gen. and sp. 
24. Doriopsis nebulosa, Pease. 
25. Onchidium melanopneumon, n. sp. 
I. Order.— NUDIBRANCHIATA KLADOHEPATICA. 
The majority of the forms belonging to this Order which were collected during the 
expedition are pelagic [Phylliroe, Acura, Glaucus, Fiona), some are littoral [Rizzolia, 
Janolus ), but only one genus [Cuthonella 1 ) was obtained from the deep sea. 
The genera Scyllwa, Bornella , Tritonia, and Marionia are transitional between the 
kladohepatic and holohepatic Nudibranchs. 
1 Up to the present time but one species belonging to the Family iEolidiadse has been found in deep water — 
Gonwol/is typica; this was dredged by M. Sars, at a depth of from 70 to 100 fathoms. — (G. O. Sars, On some remarkable 
forms of animal life from the great deeps off the Norwegian Coast, part 1, pp. 39-40, Christiania, 1872). 
