148 PEOF. OWEN ON NEW AjND EAEE CEPHALOPODA. 



The hook-armed Calamaries designated under tlie generic name Onychoteuthis by 

 Lichtenstein have since been separated and grouped under other genera, of which the 

 two best-marked are distinguished by the disposition of tlieir peculiar weapons. 



In one group the hooks or claws are restricted to the tentacles ; in the other they are 

 developed upon both arms and tentacles. 



To the first of these Calamaries the original generic term is now restricted, as the 

 type species {Onychoteuthis hanJisii^) exemplifies such partial location of the hooks. 



The term Enoploteuthis is applied, by d'Orbigny, to the group in which the arms as 

 well as the tentacles bear hooks. A fossil species similarly provided has been termed 

 Acanthoteuthis. Other genera have been proposed on minor modifications ^, but have 

 not met with acceptance. 



I propose to off'er some anatomical observations derived from a species of the first 

 genus, before describing the preserved parts of the large example of the second genus 

 of these most formidable Dibranchiate Cephalopods. 



The first observations are results of a partial dissection of a unique specimen of 

 Onychoteuthis (0. rcqjtor, Ow.), nearly allied to the type species. 



My subject (PL XXIX. figs. 1 & 2) is 8 inches 6 lines in length, of which the body 

 gives 5 inches 8 lines, including the infundibulum. The fins are rhomboidal and 

 terminal, 3 inches 2 lines across, and each of a length of 2 inches 8 lines. The arms 

 decrease in length from the ventral to the dorsal pair, but not consecutively, their 

 order, as to length, being 4, 2, 3, i. Each is provided with a double row of small 

 pyriform sessile acetabula. The swollen extremity of each tentacle, t, supports a double 

 series of hooks, each projecting from a subelongate fleshy capsule ; there are about 15 in 

 each row, the outer ones being the longest : at the base of the uncigerous expansion is 

 a circular group of small acetabula, tf, the function of which is specially noted in the 

 article Cephalopoda '^ of the ' CyclopEedia of Anatomy.' 



The eyes repeat the character of the Ommastrephic group, as noted in Ommastre- 

 j>hes ensifer, except that the "lacrymal fossa" is less marked. 



^ LoUgo ban/csii. Leach, ' Zoological Miscellany,' 1817, no. iii. p. 141, and AiDjDeudix to Tuckey's ' Narrative 

 of tlie Congo Expedition,' no. ii. p. 401. The specific name was given by Dr. Leach, under the impression that 

 the small hook-armed Cuttle caught oflf the coast of Africa might be the species noted in " Cook's Voyage" above 

 cited. In the following year (1818) the same s^iecies received from Lichtenstein [op. cit. p. 1592, no. 4, Taf. 19) 

 the name Onychoteuthis hergii. Lichensteiu's figure is copied by Eerussac and d'Orbigny in their ' Histoire 

 NatureUe des Cephalopodes,' 4to, 1835-1848, " G. Onychoteuthis, pi. v." 



^ Catalogue of the MoUusca in the Collection of the British Museum, Part I. Cephalopoda Antepedia, by 

 John Edward Gray, 12mo, 1849, p. 46 et seq. 



■* " When these latter suckers are applied to one another, the tentacles are firmly locked together at that part, 

 and the united strength of both can be applied to drag toward the mouth any resisting object which has been 

 grappled by the terminal hooks. There is no mechanical contrivance which surpasses this structure : art has 

 remotely imitated it in the fabrication of the obstetrical forceps, in which either blade can be used separately, 

 or, by the interlocking of a temporary joint, be made to act in combination." — Cycl. of Anat. vol. i. 1836, p. 529, 

 fig. 215. 



