106 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 122 



Entomacrodus chiostictus (Jordan and Gilbert) 



Plate 20 

 Salarias chiostictus Jordan and Gilbert, 1882, Proc. U.S. Nat. Mus., vol. 4, p. 363 



[deep rock pool at Mazatldn, Mexico]. 

 Entomacrodus cruentatus Garman, 1899, Mem. Mus. Comp. Zool., vol. 24, pp. 



123-124 [off Cocos Islands]. 

 Salarichthys vanderbilti Fowler, 1944, Acad. Nat. Sci. Philadelphia, monogr. 6, 



pp. 234-235 [Death River tide pools at foot of Mt. Sapo, Panama]. 



Description. — Segmented dorsal fin rays 14-16 (16 in less than 1 

 percent of specimens); segmented anal fin rays 15-17 (90 percent with 

 16), posteriormost anal pterygiophore supporting 1 or 2 external 

 elements (96 percent supporting 2); total gill-rakers on first arch 14-20 

 (15-18 in 94 percent); pseudobranchial filaments 5-7 (84 percent with 

 6), number not increasing with increase in SL; vertebrae 33-35 (34 in 

 90 percent); supraorbital cirri 1-10, number increasing with increase 

 in SL (table 48); main or longest supraorbital cirrus with all branches 

 mesially (rarely with 1 lateral branch also) ; nape with 1 cirrus on each 

 side (occasionally with 1, rarely 2, branches at tip of cirrus on one 

 side); predorsal commissural pores 3-24 (rarely more than 17), number 

 increasing with increase in SL (table 49); preopercular series of pores 

 with all positions with simple pores in 40 percent of specimens, in- 

 cluding 1-5 pairs of pores in series in 60 percent of specimens (usually 

 only 1 or 2 pairs; 92 percent of specimens with 0-3 pairs of pores; 

 fourth and fifth positions of series most frequently with paired pores) : 



number of pore pairs includ ed in series 12 3 4 5 

 frequency of occurrence 204 165 97 29 12 2 



1 pore before each anterior nostril; lateral line pores terminating on 

 side in area below and between dorsal fin spine 12 and dorsal seg- 

 mented ray 6 (usually anterior to dorsal ray 4); ventral margin of 

 upper lip crenulate on lateral thirds, entire on middle third; lip 

 crenulae usually numbering 7 to 10 on each side. 



Proportional measurements: See tables 3, 4, and 50. 



Remarks. — Males may develop fleshy rugose modifications of the 

 skin of the anal spines and the anterior first to third anal rays, similar 

 to those of E. nigricans (pi. 24/). If one considers males with these 

 modifications to be mature, the smallest mature male examined was 

 30.6 mm SL. Mature and immature males may occur in the same 

 collection and in these collections immature males may be as much 

 as 15 mm longer than mature males. 



The smallest nonophioblennius stage examined was 17.4 mm SL. 

 Ophioblennius stages examined ranged from about 16 mm (holotype 

 of E. cruentatus) to 22.5 mm. In the larvae there were one or two 

 posterolaterally directed canines on each side of the lower jaw. Where 



