1865. ] OF PHYSALUS ANTIQUORUM, 223 
of the upper and anterior surfaces. The keel in both is very thick, 
in the fourteenth grooved on its under edge. 
The following numbers represent, in inches, the greatest vertical 
and horizontal diameters of the whole of these chevron bones :— 
Greatest | Greatest 
height. length. 
BETIS fi W eter rer stovel area aterm e ayers + 132 
Seder! Ab anor ROS GOO! 93 OF 
SD TEGS tre oraletaye ei soin 9 iene « 12 103 
Iowa doer AHAB AteeDe 114 10 
HSUUG Teeetetatars siciaustste sve asic’ 103 10 
URLS cera ais)sicisic tele cia, a's 9 11 
REVOAU 34 Qode Bc dEOOCeOe 10 10 
Highth ..... Saleh nip ain 10 8 
ISTE 546 Sb aR OOD One 9 8 
AGN Saard nn eoueonenen 8 7% 
Hileventiaaetsietelsialaialele(eleiars « 7 7z 
TE weltiliiesarstsvmatelslvaya's sieves 6 7k 
Thirteenth: 1.2.5. 000%0 54 6 
Fourteenth.............- 3k 5 
There are fifteen ribs on either side ; they pass by a series of gra- 
duated changes in thickness, breadth, and curve from the first to 
the fifteenth. 
The general form of the first, looking upon its broad surface, is 
that of a slightly unequal arch. From its indistinct angle it makes 
a short quick turn towards the head, while the sternal end slopes 
with a wide bend to form the opposite longer limb of the arch. The 
head and sternal ends have each a slight twist inwards and backwards ; 
so that although nearly flat, the whole rib is not entirely in a ver- 
tical plane. The head itself is simple, somewhat roundish, broad, and 
undivided (fig. 4, no. 1), The articular surface extends the whole 
length of the broad terminal edge. There is a wide groove between 
the tuberosity and rudimentary angle. The sternal end of the rib 
is broadened and terminally truncated. 
Specimens of the first rib of this species hitherto described differ 
from each other in the development of the capitular process. The 
Rosherville and Antwerp specimens* have the head rounded and 
broad ; the specimen at the Alexandra Park and another lately ex- 
hibited near the Eastern Counties Railway, but now in the possession 
of the College of Surgeons, have, on the other hand, the process 
developed to a remarkable extent. 
In the second rib the head is somewhat triangular in shape, termi- 
nating inwards in an elongated beak-like capitular process ; the whole 
set at right angles to the long diameter of the body of the rib (fig. 4, 
no. 2). Its entire upper surface forms the articulating surface, 
which is concave. The tuberosity is well marked, as also the angle 
of the rib. The body of this rib is almost a third longer than the 
* W. H. Flower, ‘On the Skeletons of Whales in the Museums of Holland 
and Belgium,” Proc. Zool. Soc. 1864, p. 415. 
