PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 307 



Voul uormal, immediately iu front of the anal, without iiapilla. 



Air-bladder apparently wanting. Pyloric ccjeca about G, rather long. 



Bones all soft and flexible, as in Icostens amigmaticns. The skin, how- 

 ever, not thick and tough, as in the latter species, but thin and scaled. 



Coloration in spirits plain brown, lighter below; the skin somewhat 

 punctulate. 



Measurements of typical example. 



Total leugtli 7.5 iuclie.s 



Length to base of caudal 6. 8 inches = 100 



Greatest dejith 25 



Least (lei)th 9 



Length of head 20 



Diameter of eye 5|^ 



luterorbital width 5^^ 



Distance from snout to dorsal :i7 



lieugtli of base of dorsal 51 



Height of do rsal 7 



Distance from snout to anal .50 



I?ase of anal 32 



Length of pectoral 11 



Length of veutral 8 



Number of tin rays : 



Dorsal..!. 39 



Anal 28 



Scales in lateral line (ca) 120 



The single example of this species at present known was obtained in 

 the market of San Francisco by Mr. W. G. W. Harford, with two of the 

 original types of Icosfeus (vnigmaticm. It has been presented by the 

 California Academy of Sciences, for whom it was originally obtained, to 

 the United States lisTational Museum. Its si^ecific distinctness from leos- 

 tcHs (vnigmaticus was first noticed by Mr. Lockington, and we have seen 

 fit to name the species for him, in recognition of his imiiortaut work in 

 Californian ichthyology. 



The two species are called "deep-Avater fish'' by the dealers. 



As before noticed, the relations of this genus are evidently with the 

 associated genus Icosteus, but the two genera bear little resemblance to 

 any form known to us. They will })robably constitute a distinct family 

 or subfamily, in the Trachinoid group. 



This family {Icosteidcv) may bo defined as follows: 



Body oblong, compressed. Head moderate, unarmed ; the suborbital 

 without bony stay. Mouth terminal, little oblicpie ; the premaxillary 

 not })rotractile; the maxillary slender. Teeth nunute, sharp, erect, in 

 one series on the jaws only. No barbels. Gills -1, a slit behind the 

 fourth. Gill-openings wide; the membranes free from the isthmus. 

 Gill-rakers slender. Branchiostegals 7. 



Dorsal and anal fins long, without spines. Caudal fin, with many 

 recurrent accessory rays, on a slender peduncle. Pectoral fins rounded, 

 with the carpal bones slightly exserted. Ventral fins thoracic, I, 5, or 

 I, 4. Vent normal, without anal papilla. Pseudobranchiie present. 



