232 Transactions.— Zoology. 
would very soon be worn down. It looks like a mere rudiment. In one of 
my specimens (both from the Brothers) this third cone was present, in the 
other absent. The one in which it was absent was not, I think, an old 
specimen ; its teeth are in good order and very little, if at all, worn. This 
therefore cannot be a specific distinction. Drs. Günther and Knox disagree 
in the number of teeth assigned to each maxilla and palate, but this arises 
from the fact that Dr. Knox considers several of them complex teeth, while 
Dr. Giinther counts each cone as a distinct tooth. Giinther says there are 
about eighteen teeth in each maxilla which Knox counts as six. I counted 
sixteen in mine and thirteen on each palate. Of the latter the largest and 
strongest were in the middle. The teeth of the maxilla press the food 
between the parallel rows of teeth, maxillary and palatine, and enter the 
groove between them. Thus the three sets of teeth are differently sharpened ; 
the mandibular teeth have both inner and outer sides ground by the others, 
while the maxillary are sharpened on their inner and the palatine on their 
outer faces. The teeth in my specimens were thirteen in the palate, of 
which the anterior were very small. In the mandible nineteen, a canine and 
incisors, two in number, and confluent at the base. The teeth in mandible 
and maxilla near the incisors are very small, and are soon worn away or 
ground very small. In the other specimen was an additional incisor. 
The muscles which move the lower jaw are very short, thick, and 
powerful. _ The crushing force of the jaws is very great. 
The tongue is thick and rough, the glottis a long narrow slit, with 
closely-meeting raised edges. On forcibly opening the mouth of a living 
specimen the tonsils appear very large. : 
The posterior nares, two slits in the roof of the mouth, are situated just 
inside the maxillary teeth at the junction of maxillary and premaxillary 
bones. 
Thorax, Abdomen, and Pelvis. 
This large cavity is not divided by a diaphragm, though a portion of the 
peritoneum is attached to the ribs where a diaphragm might be expected. 
The peritoneum is a delicate membrane, in some parts colourless and trans- 
‘parent, in others darker. The peritoneum is almost black in and near the 
pelvis, but in many parts is much lighter, in some being of a greenish- 
brown tint. The peritoneum lines the whole of the trunk cavity, and gives 
off various large processes which attach the different organs to the spine ; 
of these the largest are those which attach the rows of eggs to the spine. 
The processes attached to the oviducts are black, but the mysentery is 
transparent. The processes are half-an-inch in breadth, allowing the rows 
: . of eggs to rest on the abdominal walls, In the mysentery are long grey 
bodies, eorpora adiposa. 
ee ee Oe Te 
EUR ER Teen a et ene = 
ERN EET A I E ua ORS TEO 2 
A pos NEA QUE E EA EIU E e OR ee ERROR A e Re Ia S ied Ps MSD IE e PE SERRE ae RR DR 
