lidae. 



SCOPELID FISHES. 123 



caught it weighed 30 lbs. and measured 48 inches in length 

 and 23 inches in girth. Pike under 4 lbs. are usually called 

 " Jack." 



The Umbras or Mud-minnows include one species {Umbra Umbra. 

 crameri) which occurs in Hungary and the countries around, and 

 two others [Umbra limi, 409, and Umbra pygama) which are 

 inhabitants of the eastern slope of the American continent and the 

 Mississippi valley. The jaws are not produced as they are in the 

 Pikes, and the teeth are all small. The dorsal fin is set more 

 forward than in the Pikes and the scales are relatively larger. The 

 Umbras frequent still waters and are most at home in muddy and 

 reedy ponds ; when startled they burrow tail foremost into the 

 mud. They are small, sluggish and carnivorous. 



Tbe family Scopelidae is a fairly large one, comprising pelagic Scope- 

 and deep-sea fishes and some extinct forms from the Cretaceous and 

 Tertiary deposits. The premaxillary bones are long, and exclude 

 the maxillse from sharing in the support of the upper border of 

 the mouth ; the parietal bones are separated ; there are no 

 transverse processes to the vertebrae ; the post-temporal is forked. 

 An adipose dorsal fin is frequently present, and in the deep-sea 

 forms luminous areas (photophores) occur in the skin of the body 

 and head. 



Scopelus (413) is a genus with many species, mostly of small 

 size, with large eyes and with photophores. While some are 

 confined to the depths of the sea others are pelagic, and others 

 again remain in deep water during the day and come to the surface 

 at night. Many of the species occur in the Mediterranean, others 

 in the Atlantic and Pacific Oceans. In the Case of Deep-sea Fishes 

 (Cabinet-case 44) are shown two curious forms belonging to this 

 family. Bathypterois (983) is a small-eyed fish, first obtained by 

 the " Challenger/'' remarkable for the great elongation of the 

 uppermost rays of the pectoral fins, which are forwardly directed 

 and act as " feelers." The foremost rays of the pelvic fins are also 

 elongated, though not to the same extent as those of the pectoral, 

 and by these doubtless the fish feels its way along the bottom of 

 the sea. Ipnops (976) is a still more remarkable fish, dredged by 

 the " Challenger " from 1600-2000 fathoms, with no eyes, but 



