314 TKUTHlDIDJi. 



the orbits than posteriorly » The praefrontals form a prominent edge 

 of the orbit, Avhich is minutely denticulated. Turbinals largo, united 

 on the median line ; prteorbital broad, the other four infraorbitals 

 naiTow. The maxillary and intermaxillary are tu'mly and immoveably 

 joined together ; the motions of the upper jaw are very limited, the 

 intermaxillary having scarcely a posterior process. The lower jaw 

 is short and broad, like the upper, similar to the bill of a parrot. 

 The bones of the tympanic cavity are well ossified. The limbs of 

 the praeoperculum meet at a rather obtuse angle, the posterior being 

 not twice as long as the inferior : operculum narrow, elevated, with 

 vertical striie ; it does not extend downwards to the angle of the 

 praeoperculum, where it is replaced by the suboperculum : the sub- 

 operculum is situated along the lower limb of the praeoperculum, and 

 has a singular flap-like process at its lower margin. The pharyngeal 

 teeth are extremely feeble ; the two lower bones form together a 

 triangular piece, on which very fine teeth are disposed in transverse 

 series ; the two bones, however, are separate and moveable. 



The radius has a rather considerable extent, but it leaves a wide 

 ovate free space behind the humerus ; eai-pal bones small. The 

 second piece of the coracoid is exceedingly long, and extends along 

 the whole of the side of the abdomen, where it is joined to a spinous 

 process of the first interhaemal : the abdominal cavity of these fishes 

 is siuTOimded by a complete ring of bones. The pubic bones are 

 slender, long, firmly attached to each other, without leaving a free 

 space between them ; they are fastened by a long process, which 

 passes the symphysis of the radii and extends on to that of the 

 humeri. 



The vertebral column of all the species of Teuthis appears to be 

 composed of ten abdominal and thii'teen caudal vertebrce, the length 

 of both portions being nearlj^ equal. The vertebrae are somewhat 

 elongate, not compressed. All the apophyses are strong, and those 

 of the anterior caudal vertebrae rather long ; most of them are di- 

 lated into broad transparent lamellae posteriorly. The intemeural 

 and interhaemal of each dorsal and anal spine have a separate neural 

 or haemal to itself, whilst the soft rays always have two interneurals 

 and interhaemals attached to one neural or haemal. The first inter- 

 neural and interhaemal are strong, armed anteriorly with a spine 

 directed forwards ; the whole of their structure is similar to that in 

 Scatoplmgus (see vol. ii. p. 59). Each intemeural is expanded su- 

 periorly into an oblong and shghtly concave plate, which has ante- 

 riorly a notch on each side, and posteriorly a short process. The 

 two articulatory processes of the dorsal spine belonging to the 

 internexu'al are fitted into these notches, whilst the posterior process 

 of the plate is received into a groove of the spine following, thereby 

 allowing the erection of the latter only to the vertical line. The ribs 

 are feeble, without epipleurals. 



lines. 



Length of the first vertebra 1 



of the second vertebra 1 j 



of the third vertebra 2\ 



