e 



111) CAUI-UKNIA AlAUKMV Or tJClKNlKS 



an«;iilati'il. Both oaiulal lobes are inodiiccd into filaments, the upper the loiij^er. 

 The fin is very ileeply forked, the median rays but one-fourth the lon<;est rays of the 

 upper lobe. The lateral line is discontinued at the anterior edge of the yellow 

 blotcii below last dorsal rays. It contains 10 or 20 scales. Each of the scales of the 

 median series on caudal peduncle i-; distinctly pitted, ami eoiitaiiis a small tube which 

 is apparently imperforate, and represents the vanishing stages of the lateral lin( 

 which formerly occupied this region. The median series of scales on the trunk con 

 tains 2S to 30 scales. Between the lateral line and the dorsal sheath are 2i rows 

 of scales. 



Tlie dorsal contains 12 spines and 13 rays; the anal fin 2 spines and 12 rays. 



C. atrilobattts resembles strikingly in coloration C. no(aiut< from .Ta|)an; but 

 the latter is deeper, and has 13 dorsal spines, larger scales, and a black-edged 

 anal fin. 



262. Pomacentrus rectifreenum Gill. 



A large number of adult specimens, 15 to 18 cm. long, are referred to this 

 species. 



Two very closely related, yet distinct, species were found associated around rocky 

 islands in Panama Bay. They were separated in the field by their slightly different 

 color and proportions, characters to which we can now add a slight but i>erfectly 

 constant difference in the fin-counts. Owing to the absence, among our Panama 

 material, of series illustrating changes which occur with age, and to the lack of adults 

 from any other region, our identification of one of these forms with the Mexican 

 species reciifrcenum is subject to some uncertainty. The second form is described 

 below as a new species (P.giUi). Our specimens of reciifrcenum are almost uniformly 

 light brown, with darker edges to the scales. The head is darker than the trunk, 

 and the ventral and vertical fins are black. The pectorals are distinctly blackish, 

 with a light blotch on the upper rays near the base. A small black spot occu2)ies the 

 extreme base of the uppermost ray. In the majority of specimens, no traces persist 

 of blue spots, but in others of full size, there are very distinct blue spots on the sides 

 and top of head, and on the scales covering the anal fin. In one specimen 14 cm. 

 long, there are in addition distinctly visible the vertical blue streaks on the scales of 

 the sides, which are characteristic of the young of recdfrcenum. 



There are constantly 15 soft dor.sal rays, and 13 anal rays, the last split ray 

 being in each case reckoned as one. These numbers hold in our Panama specimens 

 (thirteen in number), and are also found in two young sjiecimens of rediframim (all 

 to which we have access) from Mazatlan. In Gill's description of the types of redi- 

 frceniim, he assigns to it IG dorsal rays and 15 anal rays. It is reasonable to suppose 

 that the split ray at the end of each fin was by him reckoned as two rays. In giving 

 an account of some of the tyi:)e material furnished him by Dr. Gill, Dr. Giinther 

 gives 15 dorsal and 14 anal rays. In their description of the species, Jordan and 

 Evermaun assign 13 rays to each fin, but this is certainly an error. 



