Fig. 31.—Lower pharyngeals of a Parrot-fish, Scarus strongylocephalus (Bleeker).

Below in the vertebræ of the posterior half of the body the hæmapophyses (69) unite to form the hæmal spine (70), and through the hæmal canal thus formed passes a great artery. The vertebræ having hæmal as well as neural spines are known as caudal vertebræ, and occupy the posterior part of the body, usually that behind the attachment of the anal fin (78).

The anterior vertebræ known as abdominal vertebræ, bounding the body-cavity, possess neural spines similar to those of the caudal vertebræ. In place, however, of the hæmapophyses are projections known as parapophyses (72), which do not meet below, but extend outward, forming the upper part of the wall of the abdominal cavity.

Fig. 32.—Pharyngeals of Italian Parrot-fish, Sparisoma cretense (L.). a, upper; b, lower.

To the parapophyses, or near them, the ribs (73) are rather loosely attached and each rib may have one or more accessory branches (74) called epipleurals.

Fig. 33.—Roccus lineatus. Vertebral column and appendages, with a typical vertebra. (After Starks.)