590 MR. F. E. BEDDARD ON THE | Dec. 3, 
Buceros lunatus and B. bicornis, which are both large species, 
hardly present any differences from B. rhinoceros. 
Bycanistes subcylindricus has a syrinx which, although of about 
the same size as that of Ceratogymna elata, shows certain differences 
which are worth putting on record. In the first place, the syrinx 
is much compressed from side to side at the level of the last tracheal 
ring ; in the second place, the last tracheal ring is very much more 
arched than usual; it forms indeed almost a complete semicircle. 
The intrinsic muscle of the syrinx in this, as in the other smaller 
Hornbills, is very much larger relatively than in the larger species. 
Anthraceros malayanus, again, is a little different from all the types 
hitherto described. The last tracheal rings are but little fused 
posteriorly, only the penultimate and antepenultimate rings are so 
fused, so that it is impossible to be certain as to the origin of the 
pessulus. The intrinsic muscles are slender. 
Toccus presents certain peculiarities which I have not yet observed 
in any other Hornbills; the trachea has two pairs of extrinsic 
muscles given off about 3 an inch apart. This condition seems to 
me to be so remarkable that I have preserved the specimen which 
shows it, though unfortunately the insertions of the anterior pair of 
muscles are lost and I have no recollection of where the point of 
insertion was. The intrinsic muscles are relatively small. There 
appears to be no fusion between any of the tracheal rings. 
Myology. 
The arrangement of the semitendinosus and adductor in dceros 
nipalensis, which is somewhat complex, will be understood from the 
accompanying drawing (woodcut, fig. 3, p. 591). 
The semitendinosus (St) is inserted on to the tibia by a long 
thin flat tendon; another tendon joining the first just where it 
passes into the muscle is attached to the gastrocnemius. 
The accessory semitendinosus is in two parts: the larger half 
(Ast) is attached to the semitendinosus just behind the origin of 
the tendon of insertion of the latter; the second half appears 
to arise from the tendon which connects the semitendinosus with 
the gastrocnemius, it passes up towards the thigh, and just in front 
of its (tendinous) insertion on to the femur it receives a tendon 
from the adductor. This latter muscle (the adductor longus) is 
inserted by three tendons:—(1) to the femur; (2) asmall tendon 
which has already been described as joining the second half of the 
accessory tendinosus ; and (3) near to the origin of one of the internal 
heads of the gastrocnemius; to this tendon is also attached the 
inner head of the gastrocnemius. 
The corresponding muscles’ of Bucorvus abyssinicus are rather 
simpler than in Aceros nipalensis. The adductor longus is only 
inserted at two places: first by a fleshy insertion along a considerable 
length of the lower border of the femur; second by a tendon in 
1 Gadow figures most of these muscles in Bronn’s ‘ Thierreichs,’ Aves, Bd. vi. 
Abth. iv. Taf. xxiii. 0. fig. 1. 
