708 ANNEXE I 
reach the frontals. If at an early period the osteoblasts transferred their 
action to the beak, the shrinking teeth could supply the lime salts. The 
flattening out of the premaxillæ and the manufacture of the rostral 
cylinder, follow naturally from the altered conditions. The appearance 
ofthe vomer in the palate and in the floor of the rostral cylinder is signi- 
ficant in pointing to a still earlier reptilian connection. 
The following is the letter announcing the arrival of the Mesoplodon. 
Dear Sir. A large fish covered with a kind of hairy fur, is reported to 
be washed ashore at South Aran. its dimensions are length 6,56, girth 
3°,75, will you please inform me of its name and oblige ». 
Two Species of M. bidens (Ziphius Sowerbyi) were found on the west 
Coast of Ireland many years ago. 
An account of the skull of Mesoplodon Layardi is given by Sir William 
Turner! who refers to the observations of Sir William Fcower, D' 
Hecror, Prof. Mosezey and Dr. von Haasr. The measurements of the skull 
in some specimens are given and compared with those of a Ziphius of 
New Zealand and one from Shetland and the skull in Mesoplodon Sower- 
by. The length of the adult WMesoplodon Layardi examined was 1,098, 
that of the skull of the young specimen 0",635. The descriptions had 
reference to one complete skull and a part of a skeleton, a skull with 
out the lower jaw and a rostrum. The skull figured is so like the skulls 
in the Galway Museum, that one can have little difficulty in recognising 
the relationship. The descriptive particulars given concerning the adult 
skull correspond in their main feature with those which have been noted 
with regard to Mesoplodon Hectori Gray. Sir William Turner mentions 
that in the absence of a knowledge of the sex of the individual, it is im- 
possible to draw conclusions with reference to the specific value of the 
teeth, and has pointed out the generic value of the tympanie bone in 
enabling one to distinguish between Ziphius and Mesoplodon. 
Mr. MoseLeys notes are given. One animal had «large tusks» in the 
lower jaw. The density of the bone in the second specimen is referred 
to, the first specimen measured 5" — 5".625 and the second seems to 
have been 5,62. Both specimens were from the cape of Good Hope, a 
third much smaller 42°°,7 came from the East Falkland Islands. A previ- 
ously found skull had been described by Dr. Gray and Prof. Owex. 
Skeletons are mentioned from New Zealand. AI the Mesoplodon Layardi 
species are southern. 
The mesorostral bone was absent in the third specimen of the first lot 
because the specimen was immature the lengths given for the mature and 
young specimens of Mesoplodon Layardi correspond (at least the for- 
© W. Turner. Report on the Bones of Cetacea collected during the voyage of 
HMS Chalenger. London, 1880. 
