APPENDIX. 353 
Fam. Empiotocipa”.* 
(Ginther: Fishes, Vol. IV. p. 245.) 
Body compressed, elevated, or oblong, covered with 
cycloid scales. Lateral lines continuous. One dorsal 
fin, with a developed spinous process, and with a scaly 
sheath along the base, which is separated by a groove 
from the other scales ; anal with three spines and nume- 
rous rays. Ventral and thoracic fins with one spine and 
five soft rays. Tusk in the jaws small; palate smooth. 
The lower pharyngeal bone triangular. Branchiostegals, 
five orsix. Gills, four pseudo-branchiz, well developed ; 
air-bladder large, simple. Stomach without cecal 
appendage; pyloric appendage, none.  Viviparous. 
Vertebree 17—20. (Ditrema aggregatum.) 
Synopsis of Genera. 
Dorsal spines . . 7—11 . . 1. Dirrema. 
Dorsal spines . . 16—18 . . 2. Hysrerocarpus. 
DITREMA. 
Body compressed, elevated, covered with cycloid 
scales of moderate or rather small size; mouth rather 
small; teeth conical, in a single series. One dorsal fin, 
the spinous portion of which is less developed than the 
soft, and composed of seven to eleven spines; anal with 
three spines and numerous closely-set rays. Gills, four, 
with a cleft behind; pseudo-branchiz well developed. 
Ditrema. Ditrema. 
Jacksoni. Caryi. 
laterale. ageregatum. 
Temminckii. furcatum. 
vacca. brevipinnes (Gunther: xov. 
toxotes. sp. Fishes, Vol. IV.). 
* Vide Viviparous Fishes, Vol. I. 
VOL. II. AA 
