235 ? 
bels. Month without lips. 'N'asal duct with 
cartilaginous rings penetrating the palate. Median 
tooth on the palate, and two comh-like series of 
teeth on the tongue. Branchial apertures at a 
great distance from the head. The inner branchial 
ducts lead into the oesophagus. A series of mu- 
cous sacs along each side of the abdomen. Intes- 
tine without spiral valve. Eggs large with a horny 
case provided, with threads for an adhension. 
“ Inhabitants of the seas of the temperate regions 
of both hemispheres ; burroAV into other fishes, and 
feed on their flesh.” (Gunther.) 
Bdellostoma Girrhatum (Bloeh., Sciineid., p. 582,) was found 
by Forster in New Zealand. 
Sub- Class VI. LBPTOCAEBII. 
Skeleton membrane, cartilaginous and notoch- 
ordal, ribless, no brain. Pulsating sinues in place 
■ of heart. Blood colourless. Bespiratory cavity 
confluent with the abdominal cavity; branchial 
clefts in great number, the water being expelled by 
0 an opening in front of the vent. Jaws none.” 
CIEEOSTOMI. 
“Body elongate, compressed, scaleless, limbless. 
Mouth a longitudinal fissure, with subrigid cirri on 
each side, inferior. ' Vent at a short distance from 
the extremity of the tail. A low rayless fin-like fold 
