204 THE VOYAGE OF H.M.S. CHALLENGER. 



is used. From the development of its luminous organs, which cover in great number not 

 only the lower but also the lateral parts of the body, we may infer that its habits are 

 nocturnal. It is not known to what depth it descends during the daytime, but it is 

 very improbable that the two specimens from Station 101 were caught at the depth of 

 2500 fathoms. 



No more is known about the habits of the other species of the genus which have 

 been described, viz., Astronesthes richardsonii (Poey), Astronesthes barbatus (Kner),^ 

 Astronesthes martensii (Klunz.), Astronesthes clirysophehadion (Blkr.)." 



Stomias, Cuv. 

 Stomias boa. 



Esox boa, Risso. 



Stomias boa, Cuv. Val., vol. xviii. p. 368, fig. 545. 



„ barbatus, Cuv., Efegne animal. 



,, „ Bonap., Faun. ital. Pesc. (c. fig. mala). 



1 refer to this species a specimen obtained south of Australia, Station 158, in 1800 

 fathoms, as it agrees with the only detailed and reliable description and figure which 

 have hitherto been given of the Mediterranean fish, viz., by Valenciennes. Peters^ also 

 states that he has not found any diflference between a specimen from Nice and one from 

 the Pacific, caught in lat. 42° 56' S., and long. 149° 26' W. However, I must not omit 

 to mention that none of the authors referred to have given the number of luminous 

 spots along the abdomen, and that, not having a specimen from the Mediterranean, I 

 am consequently unable to assert the agreement of our fish in this respect ; also that 

 Valenciennes has counted seventy-two scales along the side of the body, whilst our 

 Antarctic specimen possesses eighty-eight. Ussow,* in his valuable contribution to our 

 knowledge of the structure of the luminous spots, states that Stomias barbatus and 

 Stomias anguilliformis'' possess fifteen luminous spots in a series from the caudal fin 

 to the anal, thii-ty-five from the anal to the ventral, and twenty-two from the ventral to 

 the pectoral. But these numbers difi"er so much from my own observations that I 

 cannot help thinking that by some error the numbers were confused in his table. 



As a full description has been given of Stomias elsewhere, I append here only a 

 diagnosis taken from the Antarctic specimen. 



''■ = Stomias leucopterus, Eyd. and Soul., Voy. Bonite. Zool., torn. i. p. 193, pi. vii. fig. 4. 



2 A fish mentioned and figured in La Nature, 1884, p. 185, under the name of " E astomias obscurus (N. S. N. S., 

 L. Vaill.)," is not characterised, but the figure represents it witli a long barbel terminating in a phosphorescent button- 

 like swelling ; it was captured in the Atlantic during the voyage of the " Talisman " at a depth of 2700 metres. 



2 Monalsber. d. k. prexiss. Akad. d. JViss. Berlin, 1876, p. 846. 



* Bull. Soc. imp. des Nat. Moscou, 1879, p. 108. 



^ A name for which I have unsuccessfully searched ichthyological literature. 



