NO. 2133. FISHES TAKEN BY "ALBATROSS;' JSSS— THOMPSON. 463 



Dorsal fin inserted behind ventral base, a distance equal to half 

 length of head; ventral bases slightly nearer posterior end of head 

 than anus, length including filamentous ray tips about three-quarters 

 head length; both dorsal and anal rays inserted between pairs of 

 short stout spines as usual. 



Luminescent organs in two rows on each side of l)ody in a ventral 

 and lateral series; in either series these number 28 between isthmus 

 and ventral fin bases, and 20 between ventrals and anus; they are 

 both continued along each side of anal fin to where body is broken 

 off; hyoid region with 12 or 13 organs; one on each branchiostegal 

 ray base, apparently 16 in number; a larger organ behind eye above 

 middle of upper jaw; a great many luminescent organs of very small 

 size scattered thickly over head and in transverse rows on body. 



From the four known species of this genus, as enumerated by 

 Brauer,^ this species seems to be differentiated by the origin of the 

 dorsal behind the ventrals, by the number of luminescent organs 

 and the position of the ventrals midway between head and anus. 

 Although the barbel is shorter than in IdiacaMhus ferox Giinther, 

 the present species is evidently nearly related to that form. If the 

 absence of teeth on the tongue is of importance, it is the only species 

 lacldng them in the genus. 



• 7. ATHERINOPSIS MICROLEPIDOTA (Jenyns) 



Atherina microlepidota Jenyns, Voy. Beagle, Fish, vol. 4, 1842, p. 68, jjI. 16, 



fig. 1. Valparaiso (not of Kner, Girard, or Giinther). 

 Atherinopsis regius Steindachner, Denlc. Akad. Wiss. Wien, vol. 72, 1902, p. 39. 



Rio Tambo, Peru. — Eigenmann, Princeton Patagonian Exped., vol. 2,pt. 



2, 1909, p. 282, no specimens. 



Tome and Lota, Chde, numerous specimens, the largest 365 mm. 

 in total length. 



This species has recently been referred to Menidia regia (Hum- 

 boldt and Valenciennes) by Eigenmann ^, Steindachner, and Smitt, 

 but in the absence of positive evidence to the contrary the disposi- 

 tion of the name regia is that made first, namely, by Giinther,"^ where 

 the species Atherina laticlavia Cuvier and Valenciennes is considered 

 its synonym. 



The two species Menidia laticlavia (Cuvier and Valenciennes) and 

 Atherinoi^sis microlepidota (Jenyns) are very different, (1) the pre- 

 maxillaries in the latter being nonprotractile, (2) body slender in 

 form, with (3) dull lateral stripe, (4) scales with basal radii, and (5) 

 the base of the anal does not extend as far posteriorly as that of the 

 second dorsal. A careful examination of the synonymy shows that 

 there has been a confusion of the two names, and that the specimens 

 of Kner, Girard, and Giinther were ones with protractile premaxil- 



• Deutschen Ticfsee Expedition, p. 50. a Cat. Fish. Brit. Mus., vol. 3, p. J02. 



• Princeton Patagonian Exped., vol. 2, 1909, p. 282. 



