2594 DiiUctin //, United States National Jlluseicm. 



black; peritoneum dusky silvery. Coast of southern California. Many 

 specimens taken at Alhatross Station 2980, in 603 fathoms. (Aez'o?, smooth; 

 XsnU, scale.) (Gilbert.) 



Maerurits (Lionurus) liolepis, GILBERT, Proc. U. S. Nat. Mus. 1890, 117, coast of southern 

 California, at Albatross Station 2980, in 603 fathoms. 



Remotely related to the Scombriform fishes, and perhaps derived from 

 the same ancestral stock as the Trichiurida', is the singular 



Suborder T^ENIOSOMI. 

 (The Kibbon-Fishes.) 



This group is thus define<l by Dr. Gill: 



" Scapular arch subnormal, post-temporal undivided and closely applied 

 to the back of the cranium, between the epiotic and pterotic, or upon tbe 

 parietal; hypercoracoid perforate at or near the margin; cranium with 

 the epiotics enlarged, encroaching backward and juxtaposed behind, inter- 

 vening between the exoccipitals and supraoccipital ; prootic and opisthotic 

 represented chiefly by the enlarged prootic; suborbital chain imperfect; 

 the copular bones separated by intervening cartilaginous elements; the 

 hypopharyngeals styliform and parallel with the branchial arches; epi- 

 pharyngeals in full number (4 pairs), and mostly compressed ; the dorsal fin 

 composed of inarticnlati? rays or spines, separ.able into lateral halves, and 

 the ventrals (when present) subbrachial. A myodouie nuiy be present oi' 

 absent, none being developed in the lie gale aid a', but 1 being distinct and 

 siipplemonti'd by a dichost in the Trachyterida'." (Gill.) 



''The ribbon-fishes," says Giiuther, "are true deep-sea fishes, met with 

 in all parts of the oceans, generally found when floating dead on the sur- 

 face or thrown ashore by the waves. Their l>ody is like a band, specimens 

 of from 15 to 20 feet long being from 10 to 12 inches deeji and about an 

 inch or two broad at their thickest part. The eye is large and lateral; 

 the mouth small, armed with very feeble teeth; the head deep and short. 

 A high dorsal fin runs along the whole leugth of the back, and is supported 

 by extremely numerous rays, its foremost portion, on the head, is detached 

 from the rest of the fin, and composed of very elongate flexible sj^ines. 

 The anal fin is absent. The caudal fin (if preserved, which is rarely the 

 case in adults) has an extra-axial position, being directed upward like a 

 fan . The ventrals are thoracic, either compressed of several rays or reduced 

 to a single long filament. The coloration is generally silvery, with rosy 

 fins. When these fishes reach the surface of the water the expansion of 

 the gases within their bodies has so loosened all the parts of their muscu- 

 lar and bony system that tliey can be lifted out of the water with diffi- 

 culty only, and nearly always portions of the body and fins are broken and 

 lost. The bones contain very little bony matter, and are very porous, thin, 

 and light. At what depth ribbon fishes live is not known; probably the 

 depths vary for difl'erent species ; but although none has yet been obtained 

 by means of the deep-sea dredge, they must be abundant at the bottom of 

 all oceans, as dead fishes or fragments of them are frequently obtained. 



