2 University of Michigan 



Atherina harringtonensis araea Jordan and Gilbert.^ — A large 

 series (Cat. No. 15307, Indiana University) characteristic of this 

 subspecies was collected by Henn and Wilson at Tumaco, Colombia. 

 Neither this form nor the preceding species has been recorded 

 from the Pacific Ocean, and neither was mentioned by Mr. Wilson 

 in his report^ upon the collection of which this marine material 

 comprises a part. 



Genus THYRINA Jordan and Culver 



Especially in view of the characters of the new species de- 

 scribed below, Atherinichthys pachylepis can scarcely be regarded 

 as typical of a genus (Thyrinops)s distinct from Thyrina. 



Although probably not an unnatural unit, this genus comprises 

 several sections, well distinguished by technical characters, and 

 possibly worthy of subgeneric distinction. 



Diagnostic Analysis of the Species of Thyrina^ 



a'. Belly less shortened, the origin of the anal fin about midway between head 

 and caudal base in adult: Atlantic slope from Venezuela to Brazil; Pacific 

 slope from Costa Rica to Ecuador. 



b'. Anal base decidedly longer than head; anal soft rays usually more than 

 20; pectoral fin more elongate, extending to or even beyond vertical 

 from tips of pelvic fins; scales thicker, with numerous fine subparallel 

 radii; scale margins strongly but rather finely laciniate; rami of man- 

 dibles rather strongly elevated posterioriy; air-bladder showing through 

 the translucent flesh, and broadly extended backward a short distance 

 into urosome: salt and fresh uvtcrs from Costa Rica to Ecuador. 



Thyrina pachylepis (Giinther). 



b^ Anal base about as long as head; anal rays usually fewer than 20 

 (16 to 21); pectoral fins less elongate (about as long as head), extending 

 about to vertical from middle of pelvic fins; scales thinner, their margins 



3 Op. cit., p. 39. 



* Ann. Cam. Mus., 10, 1916, pp. 57-70. 



sHubbs, Proc. Acad. Nat. Sci. Phila., 1917 (1918), p. 306; Jordan and 

 Hubbs, op. cit. pp. 17, 61. 



* For synonymiies cf. Jordan and Hubbs, op. cit., pp. 5S-61. 



