548 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.41. 



Scales small, ctenoid, present everywhere save tip of snout, lips, 

 maxillary and lower jaw. Preorbital scaled. A sheath present along 

 spinous dorsal; bases of soft dorsal, anal and caudal covered. 



Color of adult in alcohol uniform on body, with indications only of 

 rows of brown dots half as large as pupil on flanks and upper surface. 

 Dorsal and caudal fins with similar spots, dorsals bordered with 

 black, first part of soft dorsal broadl3^ Anal and ventrals tipped with 

 black. Peritoneum, mouth and gill cavities clear. 



The changes which this fish undergoes during its life, particularly 

 in color, are apparently veiy marked, and have given rise to much 

 confusion and synonymy. The depth of the body becomes greater 

 with age, ranging from 35 to 40 hundredths of the body length; the 

 eye varies as usual; the dorsal spines become markedly lower in pro- 

 portion, being two-thirds to three-fourths of the the body depth in 

 the young and two-fifths in adult, ranging from 15 to 25 hundredths 

 of body length; the caudal is elongate, equal to head, and pointed, 

 with the outer rays much shorter than the central, while in the adult 

 the caudal becomes emarginate and but two-thirds of head length. 

 The anal spines also shorten, as do the gill-rakers. In color the young, 

 32 mm. in length, described as D. jnctum Sind halteatum, etc., shows two 

 very broad black stripes, so broad as to become the ground color of 

 the upper part of the body. The first runs from the snout along the 

 bases of the dorsals to the last rays, leaving an interrupted narrow 

 white line in the center of the head and occiput and a spot at the base 

 of the first dorsal ray. The second stripe, its width one-third of the 

 body depth, runs through the eye to the lower caudal rays, leaving a 

 narrow white stripe from above the eye to the upper caudal rays. 

 Below the second black stripe the body is clear, but sometimes show- 

 ing another indistinct dark band. The dorsals are black save for the 

 first spine, and the margin and last rays of the soft dorsal. In later 

 life the clear spot below the first spines spreads, splitting the first 

 black stripe into two, the dark bands narrow and traces of still nar- 

 rower ones appear below the pectorals; the dorsals are margined with 

 black, with the body bands continued on them. At this stage the 

 fish is about 100 mm. long, and has been described as Diagramma 

 hlochii, etc. The upper black line left by the splitting of the broad 

 upper one then breaks into round spots, a row of which appears in 

 the white stripe above the eye, and the previously indistinct dark 

 lines below the lowermost broad line also break up into spots, extend- 

 ing to the cheeks. The membrane between the first three dorsal 

 spines clears. This stage, 120 mm. long, has also been described as 

 a separate species. From this on the tendency is to break up the 

 stripes into round spots, leaving the dorsal margined with black. 

 With age the spots disappear from the body leaving it uniform 



