48 



CALIFOENIA ACADEMY OF SCIENCES 



Measurements in Hundredths of Letigth wtthojit Caudal. 



Species 



Locality 



Length without caudal, 

 in mm 



Head 



Depth 



Orbit 



Maxillary 



Snout 



Greatest length from pre 

 opercular ridge to gill 

 opening 



Number of dorsal rays.. 



Number of anal rays 



Number of scales 



CETENGRAULIS MYSTICETUS 



Panama 



149 

 36 

 31 



14 



15 

 22 



42 



152 



35i 

 30^ 



n 

 21 



4 



15 

 14 

 22 

 42 



CETENGRAULIS EDENTULUS 



South At/antic 



104 



33 



32 



9 



20 



5 



12 

 15 

 23 

 41 



90. Cetengraulis engymen Gilbert & Picrson. 



Cetengraulis engymen Gilbert & Pierson (Jordan and Evermann, 1898, p. 2815). 



This species differs from C. niysticetus in the much narrower union of the gill membranes, the 

 less numerous gill-rakers, and in the longer snout. Head 3 to 3.3 in length; depth 4 to 4.9; eye 4 in 

 head; dorsal 14 or 15; anal 20 to 23; vertebree 41. Body compressed, fusiform, not so deep as in 

 niysticetus or edentulus. The dorsal and ventral outlines are about equally and regularly curved in the 

 larger specimens; in the smaller specimens the ventral contour is more nearly straight. Belly trenchant, 

 but not carinate nor serrate; caudal peduncle moderate, its depth being contained 1.5 times in its 

 length. Head similar to mysticetus; the snout longer, contained 5.5 to 7 times in head, \\ times in 

 eye (the snout is contained 8 to 9 times in head, in mysticetus'). Both jaws bear minute teeth, those on 

 the maxillary largest. Branchiostegal membranes united for only f to J of the distance between tip 

 of mandible and mandibular articulation; wholly free from the isthmus. Tip of mandible directly 

 beneath the anterior border of orbit. Gill-rakers long, nine-tenths diameter of eye, 20 to 30 on the 

 upper limb, 25 to 30 on the lower limb; in five examples as follows, 25-I-30, 274-25, 30-)-26, 25-)-30, 

 23+29 to 2CHJ-25. 



The origin of the donsal is midway between base of median caudal rays and a point varying 

 between front and middle of the eye. Insertion of anal below the posterior fourth or third of the dorsal, 

 its length equaling the distance from the posterior border of the eye to insertion of pectoral. The 

 pectoral is short, 2^ to 2^ in head, failing to reach the insertion of the ventrals by half or nearly half 

 its length. Caudal deeply forked, its median rays 2\ to 3 times in head. 



Color uniformly silvery, with a distinct, well defined lateral silvery band, extending from u])per 

 angle of gill-opening to base of caudal; its greatest width equals the diameter of orbit, becoming 

 narrower on caudal peduncle. 



Length 38 to 57 mm. 



