4. PRiyTiPOMA. 299 



a. Fine specimen. St. Vincent's. From Mr. Macgillivray's Col- 

 lection. 

 I>-(1. Young. St. Vincent's. Voyage of H.M.S. Plumper. 

 e. Fine specimen. MadeLra. From the Haslar Collection. 

 /. Adult. Madeira. Presented by the llev. 11. T. Lowe. 

 (f. Adult. From the Haslar Collection. 

 h. Adidt : .skeleton. From the Haslar Collection. 



Skeleton. — The system of mueiferous channels is rather more de- 

 veloped than in other species of Pristlpoma : the two pairs of fora- 

 mina on the frontal bones are wide, and lead into spacious channels ; 

 the tiu-biual bones are elongate, and transformed into half-canals. 

 The occipital crest is elevated, triangular, and does not extend over the 

 frontal bones. Of the two lateral crests, the interior is short, without 

 free processes posteriorly, and the exterior is wide and mueiferous, 

 communicating with channels of the suprascapula and the prseoper- 

 culum. 



The maxillary is very irregularly formed, broadest near its base ; 

 it is joined by one process to the palatine bone, by a second to the 

 intermaxillary, and by a thii'd to the vomer. The posterior process 

 of the intermaxillary is longer than the descending, toothed branch 

 of the bone ; the anterior })ortion of each process is broad, the pos- 

 terior stylifonn ; the descending branch is rather narrow, without 

 any prominence. The lower part of the manchbulary is transformed 

 into a wide mueiferous channel, with four grooves, sepai'ated from 

 one another by delicate transverse ridges. The proeorbital is trian- 

 gular, with the lower side curved, and has fom* or five wide openings. 

 The remainder of the infraorbital ring is very narrow, mueiferous, 

 and -without an interior plate to support the eyeball from beneath. 



The opej'culum has two obtuse and flat points posteriorly, with a 

 deep groove between ; there is no longitudinal ridge on its inner 

 sm-face. The pra^opercuhun is very strongly built; its seiTatiu'c 

 begins near the upper extremity, the teeth becoming gradually coarser 

 at the angle, and disappearing at the lower limb. The posterior teeth 

 are horizontally directed backwards. There are four wide openings, 

 separated from one another by narrow ridges : two lai-ger ones on 

 the lower limb, one on the angle, and one on the posterior limb. 

 The suprascapida is obtusely denticidated, the coracoid entire. 



The lower part of the brain-capside is slightly swollen, and there 

 is an elongate opening before the occipital joint. The anterior por- 

 tion of the basisphenoid has a narrow sharp ridge above and below. 

 The head of the vomer is broad, rounded, and slightly concave at its 

 lower surface. 



The teeth in the jaws form broad \'illiforra bands, \x\i\\ an outer 

 scries of stronger ones. The pharj-ngeal teeth are stout, conical, and 

 placed in elongate triangular patches below, and in rounded ones 

 above. 



There are ten abdominal and sixteen caudal vertebrae the length 

 of the fonner portion of the vertebral column being to that of the 

 latter as I : l-o. There are thi-ee spurious interncural spines in 



