178 Dr. Griffitli on the Sacculi of the Polygastrica. 



racoid bone or upper axilla of tlie pectoral fin. The lower edges 

 of the suboperculum and interoperculum are free and overlap 

 the conspicuous gill-rays, which are six in number, strong, round 

 and curved. The gill-opening, though low, is moderately large, 

 and extends forwards to beneath the joint of the lower jaw. The 

 humeral chain consists of suprascapular, scapular and coracoid. 



The scales are cycloid, tiled, exposing a longitudinally elliptical 

 surface and firmly imbedded in the skin. There are about thirty 

 in a vertical row. The lateral line is composed of fifty small emi- 

 nences, and terminates opposite to the tenth dorsal ray. 



Rays :— Br. 6 ; D. 70; A. 59; C. 9; P. 10; V. 0. 



All the rays of all the fins are jointed : the first rays of the dor- 

 sal and anal are simple ; the other rays of these fins are divided at 

 their tips into about four branches which do not spread, and the 

 rays are slender and stand well apart in the strong membrane. 

 The dorsal rays increase gradually in length from the first to 

 near the middle of the fin, after which they continue equal to the 

 end of the fin. The anal is more nearly equal throughout. Both 

 fins are pointed at the end, but the points are not conspicuous, 

 the space between them being filled by the caudal fin, whose rays 

 are much finer, more crowded and somewhat shorter. The pec- 

 toral is small and rounded, its rays slender, crowded and branched. 

 The interspinous bones of the back correspond in number with 

 the dorsal rays. 



Dimensions. inches. 



Length from intermaxillary symphysis to end of caudal fin... 13-80 



■ base of ditto 13-38 



beginning of anal . 450 



centre of anus 4-25 



beginning of dorsal 2-35 



gill-opening 1-65 



centre of eye 0-65 



Length of rictus of mouth 0-60 



lower jaw 1-15 



Diameter of eye 0-22 



Heightofhead 0-95 



body about 1-30 



dorsal fin posteriorly , 0-60 



anal fin 0-35 



Length of pectoral fin 0-45 



XXIV. — Additional Observations on the Polygastric Sacculi. 

 By John Wm. Griffith, M.D., F.L.S. &c. 



To the Editors of the Annals of Natural History. 



Gentlemen, 

 A PAPER having been inserted in the last number of your Journal 

 (p. 104) by Mr. Addison, tending to the conclusion that the inaccu- 



