126 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



Figure 13. — Pelagic prejuvenile Pseudopriacanthus altus, 16.8 mm. standard length (WHOI). 



origin to midcaudal base, up (130-140 mm.), 

 figure 29. 



Although the data are not sufficiently strong to 

 support a positive statement, I believe from ex- 

 amination of a size series of specimens (figs. 11 to 

 23) that the inflections in relations of body pro- 

 portions to standard length are, at least in part, 

 a function of a general postcranial elongation of 

 the larger fish, particularly in the region of the 

 caudal peduncle, brought about by a dispro- 

 portionately greater rate of increase in length in 

 comparison with increase in body part — father 

 than a slowing down of growth in the body part 

 and a constant rate of increase in the length. 



PIGMENTATION 

 PIGMENTATION OF PRESERVED SPECIMENS 



The following descriptions are based on pigmen- 

 tation of formalin- and alcohol-preserved speci- 

 mens. In the discussion which follows, tlie word 



"pigmentation" refers only to dark chromato- 

 phores, which appear brown or black. These 

 chroma tophores remain, though varying in in- 

 tensity with type and duration of preservation, 

 for an indefinite, usually a long period of time and 

 to systematists are the most useful of all pig- 

 ment characters. 



The eye remains chirk tliroughout life. 



Body Pigmentation 



Pigmentation in the smallest specimen ex- 

 amined, 2.2 mm. (fig. 8), consisted only of (1) a 

 few internal scattered chromatophores either on 

 the upper exterior surfaces of the gut, or on the 

 lining of the abdominal cavity, and (2) dark areas 

 extending either across the anterior and posterior 

 portions of the optic lobes or on the brain case, 

 forming a pigmented area under the single cranial 

 spine. In addition, a small patch of pigment ex- 

 tended between the eyes, across the surface of the 

 forebrain, anterior to the optic-lobe pigmentation. 



