1886.] SO-CALLED PELVISTERNUM. 165 
millim, 
enatiynh nbn ft 0G ae as OPS as 140 
Wrenhray dnc. eit eth ey ile on arigizistnalSints 20 
Breadth opposite the acetabulum ............ 35 
Length of pubis ...... ee 
Interpubic bone, antero-posterior diameter .... 15 
i. », breadth of one side ........ 35 
In Phacocherus the bone occupies the position of the triangular 
ligament in man, and is three-cornered and wedge-like. The following 
measurements were made :— 
millim 
Length of os innominatum ................ 250 
Crestisee: AS f6) p Pt 120 
Breadth of lium above acetabulum LR RWAE BOSS 32 
i tebat acetabulum. soe 87 
» below acetabulum.......... 34 
Arch of Paws: Hee I sie HO Wen fo 
Interpubic bone, breadth .......00.05.. 00.0 24 
a jt superior depth’ 22.) 0) Ate a 15 
iz sy tinferior depth i) ey Ai g.s8 30 
BS >, thickness at base ..7....... 20 
In the skeleton of the Beaver the bone is not so distinct as in 
Phacocherus. The following are the measurements :— 
millim 
_Length of os innominatum ................ 160 
Cresta. ty 2K eat, 5 AW RI Oe In SAREE EOP SO 
Breadth opposite acetabulum .............. 35 
PEC OGL DUIS IN SL Su PSOE ee eh AD 
Plept eb pubic Hone, 5.260. 8eU Es eg 
Breadth-otoneshalfrogs:.) 20h stein ae. 25 
I do not find the bone present in any other mammalian skeletons 
that I have examined. The bone occupies the position of the 
triangular ligament and the os cloacze of Lacertilians. Ligaments and 
fascize are so often the seat of ossifications, and bones in one set of 
animals are so often represented by ligaments in another set, that 
one is almost tempted to regard the bones above referred to as, in 
whole or in part, homologous with the triangular ligament of the 
urethra found in the higher animals. 
The interpubic bone in Bradypus is mentioned by Prof. Flower in 
his ‘ Osteology.’ 
