LARVAL FORMS OF FRESH-WATER MULLET 



421 



specimens of 68 and 105 mm. Meek and Hilde- 

 brand (191(!, p. 834) jrive cri)] rakers on tlie lower 

 limb of tlie first an'b for -I. mont'icoJa as ranging 

 from 17 to 20. It appears that the full comple- 

 ment of gill rakers develops when the tish are 

 l)etween ;}() and 40 mm. long. Tliis increase in 

 number of gill rakei-s with increase in size also 

 occurs in other related species. A 30-mm. M. 



I MM. 



I MM. 



I MM. 



FiiiiKK ti. — .\irai)genieiit ami form of teeth in a 2!l.4-iiiiii. 

 MioniixtomHH monticola: A, left iialf of premaxilary ; 

 B, left lialf of lower jaw ; (', vomer and palatine bones ; 

 I), tongue. (Camera lucida drawings from a cleared and 

 stained sjieeimen.) 



citrenia had 30 gill rakers on the lower limb of 

 tlie first arch whereas adults have more than 

 twice that number; a 30-nnii. M. cephaluK had 

 about 25 gill rakers and a 60-mm. specimen had 

 alx)ut 40 (lower limb first arch). 



Scales: — All specimens examined had ctenoid 

 scales. Figure 7 shows arrangement of spines on 

 a scale from a 28.fi-mm. specimen. There were 

 39 to 42 (most frequently 40 or 41) rows of scales 

 in a series from the upper angle of the opercle to 

 tlie middle of the caudal base ; and 11 or 12 rows of 

 scales between the second dorsal and the anal fin. 



BODY PROPORTIONS 



Measurements from the 34 sj^ecimens examined 

 (ranging from 24.1 to 119 mm., standard length) 

 were nsed to estimate the relation between stand- 

 ard length and eye diameter, head length, body 

 deptli (at pectoral), and distances from snout to 

 insertions of the first dorsal fin. second dorsal fin, 

 and anal fin. These relationships are illustrated 

 in figures 8 and 9. and the rate of development of 

 body parts, within the range of sizes studied, is 

 apparent. The upward shift in the regression line 

 for body depth (at pectoral) occurs between sea- 

 stage and fresh-water stream material. I have 

 observed the same occurrence in .1/. cure ma be- 



I MM. 



KiciHK 7. — Scale from a 2,s.t>-mm Afloiioatoniiix monticola, 

 showing arrangement of spines. (Scale taken above 

 midline of Ixidy between second dorsal and anal tins.) 



