niSTCEY OF THE AMERICAN MENHADEN. 19 



A third species occurs in the Gulf of Mexico. It is distinguished by 

 its hirger liead and fins and other characters. It appears to have never 

 been described, and, for this form, the name of Brevoortia patronus is 

 I>roposed. It is accompanied by the same crustacean parasite that is 

 found in the mouths of B. iyrannus, to which Latrobe gave the signifi- 

 cant specific name o£ pra^gustator. 



C— DESCRIPTIONS OF THE AMERICAN SPECIES OF MEN- 

 HADEN, WITH ANATOMICAL AND PHYSIOLOGICAL 

 NOTES. 



7. — TECHNICAL DESCRIPTIONS. 



Brevoortia tyrannus. 



40. The following is a careful description of the common menhaden, 

 which occurs on the east coast of the United States and Brazil : 



ISrovooc'iBa tyraBBEioas (Latrobe) Goode. The Menhaden. 



Diagnosis. — Head and jaws short ; the length of the head less than 

 one-third of the length of the body less the caudal fin ; especially 

 short in subsp. aurea, the maxillary in length much less than three-twen- 

 tieths of the length of the body. 



Height of body about one-third of total length, in very fat individuals 

 about three-eighths. Fins comparatively short, the height of the dorsal 

 less than length of maxillary, and considerably less than three-tenths of 

 length of body; that of the anal usually less than half that of maxil- 

 lary; that of ventral always less than one-tenth of total length; the 

 length of middle caudal rays one-fifth that of body, and less that of ex- 

 terior caudal rays, iisuallj' about three-fourths, often less than two-thirds, 

 and rarely more than five sixths of total length. Fins all shorter in subsp. 

 aurea. Insertion of ventral far behind tip of pectoral. Insertion of dor- 

 sal about equidistant from snout and base of middle caudal rays, but 

 varying two or three one-huudredths to either side of this median point, 

 and always slightly behind the vertical from insertion of ventral. 



Scales of medium size, much serrated, arranged very irregularly in 

 24-2G transverse and GO-80 longitudinal rows. Scales forming sheath at 

 base of pectoral not large. Sqtiamatiou of caudal lobes moderate. Oper- 

 culum strongly striated in subsp. mcnJiaden, almost smooth in subsp. 

 aurea. Scapular blotch conspicuous. 



This species is easily distinguished from Brevoortia patronus by its 

 shorter head and fins, by its slender body and its pectinated scales, and 

 from B. pecUnata by its smaller, less regularly arranged, and more 

 numerous scales, and its shorter, less furcate caudal fin. 



Individual variations and special descriptions. 



Head. — The length of the head varies from 28 to 33 hundrdths of 

 total length. The posterior end of the maxillary extends to a point in 

 the vertical from the centre of the orbit. The length of the skull, as 



