46 



back (as represented in the Zoological Journal, vol. ii. pi. xv.), the 

 museles presenting comparatively i'ew peculiarities, since the mo- 

 tion alluded to is remarkable rather for its extent, than the vigour 

 with which it is performed. 



" The principai elevators of the tail are the sacro-cocci/gei-supe- 

 riores (sacro-sus-caudiens of Vicq d'Azyr). They arise froni two 

 longitudinal ridges on the inferior and convex part of the sacrum, 

 and are inserted into the superior spines of the first six vertebrce by 

 detached tendons, terminating broadly in the anchylosed vertebrce. 

 The principai antagonists of these museles, sacro-coccygei-injeriores 

 (sncro-sous-caudiens of Vicq d'Azyr), pass over the hrst five verte-, 

 brce and terminate in the sixth and anchylosed vertebrce : their ori- 

 gins are wider apart than in the preceding pair of museles, coming 

 offfrom the margins of the sacro-sciatic notches. In the interval 

 are situated small museles passing from the transverse proeesses to 

 the inferior spines of the first six vertebrce. 



" From the limited nature of the lateral motions of the tail the 

 museles appropriate to these movements are feeble, especialiy in 

 comparison with those vvhich are observed in the birds that spread 

 their tail-feathers in flight, and in that way regulate their course 

 during that vigorous species of locomotion. . These museles are in 

 number two on each side, arising from the posterior extremities of 

 the ischia and inserted into the expanded anchylosed vertebrce. 

 From the disposition of these museles it is obvious that after the 

 proper elevators have raised the tail to a certain height, they also 

 become dorsad of the centre of motion, combine their forees with 

 the elevators, and by this addition of power terminate the act of 

 throwing up the tail by a jerk : so Mr. Vigors in his observations 

 on the living animal observes, that 'in these movements the tail 

 seemed to turn as if on a hinge that was operated on by a spring.' 



*' The morbid appearanees observed in this dissection were con- 

 fined to the alimentary canai, vvhich exhibited in four places tracts 

 of inflammation ofoneand tvvoinches in extent." 



The stuflPed skin and skull of a Roclent Quadruped, brought from 

 Chili by Mr. H. Cuming, were laid npon the table, and eharacterized 

 by Mr. Bennett as forming a new genus, 



OCTODON. 



Dentes primores ^ acutati antice laeves ; molares utrinque -J era- 

 dicati complicati subaequales; 5!//jmorcs subtransversi, facie antica 

 lata, postica ob incisuram externam profundam duplo angustiore, 

 intern^ medio uniplicatii, plicis a primo ad postreraum sensim mino- 

 ribus ; inferiores obliqui, singulo plica externa internaque suboppo- 

 sitis coronidem in areas duas oblique transversales, figuram 8 vel 

 clepsydram quodammodo referentes, dispartientibus, plica externa 

 in postremo vix conspicua. 



Artus subaEquales omnes pentadact)'li, digitis liberis, unguibus 

 falcularibus acutis. Cauda mediocris subannulata pilosa apice 

 floccosa. 



The teeth of this animal are remarkably different from those of 



