CEPHALOPODS OF THE PHILIPPINE ISLANDS 15 



Genus JapeieUa Hoyle, 1885 



Japetella diaphana Hoyle, 1885 

 Genus Eledonella Verrill, 1884 



Eledonella pygmaea Verrill, 1884 

 Family Octopodidae 



Genus Octopus Cuvier, 1797 



Octopus membranaceus Quoy and Gaimard, 1832 



Octopus horridus d'Orbigny, 1826 



Octopus teuthoides Robson, 1929 



Octopus macropus Risso, 1826 



Octopus vulgaris Cuvier, 1797 

 Genus Cistopus Gray, 1849 



Cistopus indicus (d'Orbigny, 1840) 

 Family Argonautidae 



Genus Argonauta Linnaeus, 1758 



Argonauta argo Linnaeus, 1758 



Argonauta Mans Solander, 1786 



Argonauta nodosa Solander, 1786 



Argonauta hottgeri Maltzan, 1881 



Artificial Key to Cephalopoda of the Philippine Islands 



1. Shell external, coiled, and chambered; tentacles numerous and without 



suckers. Subclass Nautiloidea Nautilus pompilius (p. 19) 



Shell internal or lacking; circumoral appendages 8 or 10 and bearing 

 suckers. Subclass Coleoidea 2 



2. Circumoral appendages eight, the suckers without horny rings. Order 



OCTOPODA 41 



Circumoral appendages consisting of 8 arms and 2 tentacles, the 

 suckers equipped with horny rings 3 



3. Shell internal, chalky or coiled and chambered, or reduced, thin, or lacking. 



Fins either marginal and narrow or large and paddle-shaped; eyes covered 



by skin of head, not widely perforate. Order Sepioidea 4 



Shell internal, usually a thin, well-developed gladius; fins terminal or nearly 

 so, often rhombic or triangular (marginal in Sepioteuthis) , not paddlelike 

 (except in Cranchiidae) ; eyes open, perforate except in the Myopsida. 

 Order Teuthoidea 19 



4. Shell internal, coiled and chambered; fins inserted transversely; bathypelagic. 



Spirula spirula (p. 20) 

 Shell straight, thick, and chalky, thin and vestigial, or lacking 5 



5. Shell chalky; fins marginal, narrow 6 



Shell reduced and thin, or lacking; fins usually paddle-shaped 10 



6. Body rather long and slender; shell very slender; end of body projects as a 



sharp point beyond fins Sepia andreana (p. 31) ^ 



Body broad; shell moderately wide; end of body not projecting beyond 

 fins 7 



7. Suckers of tentacular club in about 10 rows, all small with no enlarged median 



suckers Sepia esculenta (p. 28) 



Suckers of tentacular club in about 4 or 5 rows, some suckers of inner 

 rows much larger than marginals 8 



2 In the key to the Sepia, S. papuensis and S. recurvirostris are not included. Specimens were not seen 

 and the descriptions are insufScient for obtaining key characters. 



