REPORT ON THE DEEP-SEA DEPOSITS. 
2S9 
derived from the examination of the Challenger samples, but may fairly be taken as an 
index of the relative frequency of occurrence of these organic fragments in all deep-sea 
deposits. 
There are 348 Challenger deposits fully described in the Tables of Chapter II., and 
the order of frequency is as follows, the number of times the various organic remains 
were observed being indicated in brackets : — 
Globigerinidee (306 times), Eadiolaria (274), Sponge spicules (271), Eotalidse (269), 
Echinoderm fragments (266), pelagic Pulvinulwse (263), Lituolidse (244), Miliolidse 
(241), Coccoliths (235), Lagenidse (211), Textularidas (201), Diatoms (181), Ehabdoliths 
(179), Ostracodes (173), Astrorhizidse (145), Lamellibranchs (121), Pteropods (119), 
Niimmnlinidse (112), Gasteropods (109), otoliths and bones of fish (102), Polyzoa (91)^ 
casts (78), teeth of fish (65), Heteropocls (61), Serpula, and other worm tubes (53), 
arenaceous Textularidae (34), calcareous Algae (27), Alcyonarian spicules (24), Coral 
fragments (23), Coccospheres (20), Dentalium (19), arenaceous Foraminifera, families 
not given (15), Brachiopods (8), Cephalopod beaks (8), Cirripedia (7), Chilostomellidae 
(1), and Crustacean fragments (l). 
There are 215 purely pelagic deposits fully described, and confining our attention to 
these, viz., the Eed Clay, Eadiolarian, Diatom, Globigerina, and Pteropod Oozes, the 
order is somewhat different, as follows; — Eadiolaria (197 times), Globigerinidse (186), 
Pulvinulina (168), Eotalidse (160), Coccoliths (155), Sponge spicules (155), Echinoderm 
fragments (153), Lituolidse (150), Miliolidse (142), Ehabdoliths (126), Lagenidse (109), 
Diatoms (99), Textularidae (97), Ostracodes (88), Astrorhizidse (82), teeth of fish (60), 
Pteropods (51), Nummulinidse (48), casts (46), otoliths of fish (43), Lamellibranchs (41), 
Gasteropods (39), Polyzoa (33), Heteropocls (22), arenaceous Foraminifera (12), Serpula, 
and other worm tubes (11), Coccospheres (10), arenaceous Textularidae (10), Dentalium 
(7), Coral fragments (7), calcareous Algae (6), Alcyonarian spicules (5), Brachiopods (5), 
Cirripeds (4), and Cephalopod beaks (4). 
g. Coral Eeefs. 
A description of coral reefs and islands, and a discussion of their peculiar features, do 
not fall within the scope of this work. The subject of coral reefs, and the bearing of 
deep-sea investigations on the question of their origin, has been dealt with by Mr Murray 
in several Memoirs.^ It may, however, be here pointed out that a recent writer,^ among 
1 Murray, “ On the Structure and Origin of (Joral Reefs and Islands, Proc. Roy. Soc. Edin., vol. x. pp. 505-518, 
1880 ; “ Structure, Origin, and Distribution of Coral Reels and Islands,” Lecture before Roy. Inst, of Gt. Brit., March 
16, 1888 ; “ The Great Ocean Basins,” Nature, vol. xxxii. p. 613, 1885 ; also Narr. Chall. Exp., vol. i. pp. 781, 782, 1885 ; 
Murray and Irvine, “ On Coral Reefs and other Carbonate of Lime Formations in Modern Seas,” Proc. Roy. Soc. Edin., 
vol. xvii. pp. 79-109, 1890. 
^ R. Langenbeck, “ Die Theorieen iiber die Enstehung der Koralleninseln und Korallenriffe, &c.,” p. 158, Leipzig, 
1890. 
(deep-sea deposits chall. exp. — 1891.) 
37 
