26 



Section II. of First Order. — The Ten-armed Cuttles, Decapoda {Leach, 1817). 



Decapoda. — Body oval or elongated, with ten arms ; two called ten- 

 tacles, very much longer than the others, with expanded terminations 

 (tentacular clubs). Mantle generally not united by a band to the head, 

 strengthened by side and vertical ridges fitting into corresponding grooves 

 in the body. Fins always present, lateral or terminal, Eyes capable 

 of motion, and either covered by a transparent skin, or exposed to the 

 water. Arms with two or more rows of suckers, which are on prominences, 

 have horny margins, and are sometimes possessed of a central hook. 

 Tentacles more or less retractile, often very long, terminating in an 

 expanded extremity, furnished with hooks or suckers. Shell (pen, 

 gladius), generally internal, lance-shape, longitudinal, (1.) Horny, or (2.) 

 Calcareous, or (3.) Chambered and curved, partly external. Funnel 

 generally valved. Twenty-one genera, Enoploteuthis, Abralia, Octo- 

 podoteuthis, Ancistrocheirus, Onychoteuthis, Dosidicus, Ommastrephes, 

 Thysanoteuthis, Chiroteuthis, Histioteuthis, Loligo, Gonatus, Eossia, 

 Sepioteuthis, Loligopsis, Sepiola, Sepioloidea, Fidenas, Cranchia, Sepia, 

 and Spirula, separated into several groups by the nature of the internal 

 shell, the plan of the mantle, and the aspect of the eyes. 



1. The Horny Shelled Cuttles, with ten arms, TEUTHIDJE (Owen, 1838). 



Teuthid^e. — Animal having a horny internal shell, belonging to the 

 divisions A. and B. ; (A.) of those without a head-band to mantle, and 

 (B.) with a head-band. 



Division A. — Of the horny shelled cuttles, Teuthidae, having the 

 Mantle not united by a band to the head, either with (/.) eyes naked 

 (without a covering membrane), or (II.) with a covering membrane. 



I Eyes naked, without a covering membrane, Oigopsidae (D'Orbigny, 1841). 



IV. — First group of the naked-eyed Cuttles, having a horny internal shell 

 without a head band. Mantle strengthend by tubercles fitting 

 into corresponding recesses. Fins lateral or terminal. Head of 

 moderate size. Eyes with a lacrymal sinus. Arms often fur- 

 nished with hooks or claws in addition to suckers. Tentacles 

 often provided with hooks in addition to the suckers, and some- 

 times with special suckers for bringing both tentacles into 

 contact, Funnel with a valve. Onychoteuthidae (Gray, 1847). 

 Eight genera, Enoploteuthis, Abralia, Octopodoteuthis, Ancis- 

 trocheirus, Onychoteuthis, Dosidicus, Ommastrephes, and Thy- 

 sanoteuthis. 



(a.) Arms and tentacles furnished with hooks. 



10. Enoploteuthis, D'Orbigny, 1839 ... Body elongate; fins terminal, triangular, 



arms with two series of concealed hooks ; 

 pen without projecting termination, 

 sides often curved. 



11. Abralia, Gray, 1849 Body conical; fins terminal, triangular; 



arms with hooks at their base and 

 suckers at their extremities, tentacles 

 with suckers alternating with hooks ; 

 pen with concave sides. 



