Royal Society. 26^ 
two tranfverle procefles, which at their extremities have fmall 
Acetabtila or Sinus's^ for the receiving the heads of the ribs, 
which are tallened to them; the fpincs of thele Vertebra are 
ilender thin, and iharp, about \ of an inch long 5 the fix follow- 
ing Vertebra of the 'Tlma^ have iliort, thick, and flat fpines, 
the oblique procefles, being continued on each fide of the Ipine, 
ipake, as it were, a gutter 5 and the tranfverle procefles here are 
Ibmewhat different from the former 5 the Ipines of the Vertebrae 
of the back, or loms, as they approached the Os Sacrum^ {q they 
gradually leflened in their thickneis on the edge 5 but here there 
were double oblicjue procefles 3 viz. four at ea'ch end of the Ver- 
rebra^ the undermoft lJ3reading themielves out in breadth 5 the 
three Vertebra of the Os Sacrim are firmly faftened to the 0% 
Mlum, but the laft not {o entirely as the two former, which at 
each fide had a broad tranfverfe procels, and the ipines of the two 
former were thin , the two firlt Vertebra of the tail had only 
one fmall acute fpine, but in all the other Vertebra of the tail, 
both at the head and tail of each Vertebra^ there were two 
ipines, but thole at the head of the joint were the largeft • in the 
fix firil Vertebra of the tail, there was on each vic^iz^ a broad 
tranfverfe procefs, the length of the joint 5 in the other Vertebra^ 
only at the head and tail, a jutting out at the fides 5 the Verte- 
bra about the middle of the tail were the longeft, beina there 
about an inch in length, but at the root and end of the tail not 
fo long: The fpines or hooks, placed in a line in the middle of 
the under fide of the Vertebra of the tail, arc a wondcrtlii piece 
of mechanifm ^ it is true, the firft three Vertebrae had none of 
thele fpines, but in all the reft they were to be obferved 5 and as 
they approached the extremity of the tail, they grew lefler and 
fliorter^ thefe fpines, where longeil, were about a quarter of an 
inch, or fomewhat m.ore ^ they were placed juft at the articula- 
tion of each joint, and in the middle from the fides, and Icemed 
to be articulated, both to the preceeding and following Vertebra^ 
not being an entire folid bone, but arifing from the Vertebr<e 
with two Crura or legs, were become afterwards perfe6lly united 
to the extremities i by this means the bones are rendred more 
ftrong and firm, and this hollow lerves for the tranfmitting the 
blood-veflels thro' them; and one may here oblcrve a Stria or 
furrow, all the length of the P^ertebra^ for the receiving them, 
whereby they are the better fecured fl'um comprefllon, wlien this 
animal hangs by its tail; and for the performing ihis ofFxce, no- 
thing could be more advantageoufly^ontyived; for when the tail 
is twiited or wound about a ftick, this hook of the Ipine eafily 
fuiiains 
