ACADEMY OF NATURAL SCIENCES. 73 



Aykesia, n. g.* 



Generic characters. — Form elongated, suboval ; the outline more curved above 

 than below. Scales large, finely pectinated, completely covering the body and 

 head, except in front of orbit ; smaller on head, and becoming very small where 

 they extend over parts of the fins and tail. 



Teeth numerous, acute, entire, the anterior row largest ; those below larger 

 than above, and flattened posteriorly. A few smaller ones crowded behind these 

 near symphysis. Pharyngeals villiform. 



Premaxillars protractile, the upper arched, twice as high as wide, the lower 

 shutting within it. 



Preoperculum entire, a very small obtuse spine at angle of operculum. 



Pectorals rather long and pointed. Caudal deeply forked, the lobes acute. 

 Dorsal long, anal moderate. 



Differs from Pomacentrus (Lacepede) chiefly in a more arched dorsal outline, 

 armed operculum and unarmed preoperculum, pointed fins and tail, proportions 

 of fins. 



The dorsal outline appears to become much more convex with age, chiefly 

 from deposit of fat on the occiput, as is the case in some Labroids, as for 

 instance, L. pulcher (Ayres) aud Julis modestus (Girard), the latter also grow- 

 ing higher in proportion to its length throughout. The dotted line represents 

 the dorsal outline of a specimen one-fourth larger than that figured, but other- 

 wise closely like it. 



Ayresia punctipinnis, Cooper, n. sp., State coll. No. 596. [Fig. 18.] 

 Specific characters. — Head forming less than a fourth of total length (0.18), 

 eyes less than one-third the length of head, and less than its own diameter from 

 end of snout, height of head behind orbit about equal to its length. Greatest 

 thickness of body about one-eighth of total length. 



Height of pectoral equal to one-fourth the distance from snout to fork of tail 

 (0.21). Dorsal commencing above pectoral joint, its spinous portion nearly 

 one-third of its total length, and one-sixth of its height, the first spine shortest. 

 Soft rays becoming three times as high, forming an obtuse point behind ; the 

 last ray about as long as the spines (the first dorsal spine should be one-fourth 

 longer than in the figure). Caudal peduncle slightly contracted, shorter than 

 caudal rays. Fork of tail extending half-way to its base, the upper lobe longest, 

 being one-fifth of the total length. Anal commencing beneath the tenth dorsal 

 spine, and ending a little anterior to end of soft dorsal, its base less than one- 

 sixth of total length (0.17). 



Br. V-V D.XIII, 6-1-6, C. 3-1-6 6-1-3, A.II-11, V. 1-8, P-19. Scales 30 4 -| J- 

 lat. line ant. 19. 



Color. — Bluish or greenish-black ; sides, paler, sometimes coppery, fins smoky, 

 the dorsal and caudal spotted with black, iris bronzed brown. Beneath whitish 

 in young, all the hues darker in the old fish. Some are also spotted on the 

 body posteriorly. 



* The name of Dr. W. O. Ayres, is well known in connection with Ichthyology, especially 

 that of California. 



