. Bulletin of the British Museum (Natural History). Zoology . 146 P. J. P. WHITEHEAD. Fig. 55. Anchoa lyolepis, showing details of head (Trinidad specimen 67-8 mm , BMNH ). Cut-away portion of lower jaw shows the distinct bulge of the urohyal (hatched). Inset, dorsal view of occipital region showing frontals (fr.) closely apposed over the anterior arm of the supra-occipital (), the posterior frontal fontanelles being virtually occluded (just visible on right side). and very slight rounded projection at upper corner (cf. prominent triangular pro- jection
. Bulletin of the British Museum (Natural History). Zoology . 146 P. J. P. WHITEHEAD. Fig. 55. Anchoa lyolepis, showing details of head (Trinidad specimen 67-8 mm , BMNH ). Cut-away portion of lower jaw shows the distinct bulge of the urohyal (hatched). Inset, dorsal view of occipital region showing frontals (fr.) closely apposed over the anterior arm of the supra-occipital (), the posterior frontal fontanelles being virtually occluded (just visible on right side). and very slight rounded projection at upper corner (cf. prominent triangular pro- jection in A. spinifer). Least (diagonal) length of cheek 1-5 eye diameters or 2-5 times in head length. Dorsal surface of head with a median ridge separating the supra-orbital canals, the latter bridged by two bony struts, the posterior lying just behind a vertical from the hind border of the pupil. Frontal tips narrowly divided in midline posteriorly, the space between them exposing a pair of crescentic posterior frontal fontanelles (o-8 mm long in a fish of 49-5 mm ) but fully occupied by the anterior arm of the supra-occipital, the fontanelles being occluded, in the largest fish (67-8 mm ) (Figure 55). Pterotic bulla large, occupying about three-quarters of pre-epiotic fossa. Posterior border of gill opening evenly rounded. Isthmus silvery, tapering evenly : forward but leaving exposed a prominent urohyal whose ventral profile bulges distinctly (Figure 55). Branchiostegal membrane narrow, covering half of urohyal 'bulge', the longest branchiostegal rays just less than snout length. Gillrakers slender, about two-thirds eye diameter and over twice length of corresponding gill filaments ; a series of about a dozen fine spines on either face of gillraker and a further series of about 50 smaller spines along inner edge of raker ; posterior face. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloratio
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