14 CHECK LTST OF THE 



(4) Lake Sturgeon. Rock Sturgeon. 



(Acipenser rubicundus.) 



Dark olive above ; sides paler or reddish often with irregular blackish 

 spots. Body rather elongate. Snout slender and long- in the young-, 

 becoming- quite blunt with ag-e. The shields are large, rough, with 

 strongly hooked spines, becoming later comparatively smooth ; ventral 

 shields growing smaller with age and finally deciduous. 



The fishermen make a distinction between the young and the old of 

 this species, calling the former Rock Sturgeon and the older fish Lake 

 Sturgeon. There is, however, but one Sturgeon in our waters ; the differ- 

 ence in the size and shape of the snout and in the number and development 

 of the spines between the immature fish and the adult is sometimes very 

 great, hence the idea that two species are found. 



The Lake Sturgeon is found in the Great Lakes and all the larger 

 rivers falling into them, and is a food fish of considerable commercial 

 importance, its flesh being used either fresh or dried and smoked. From 

 its roe, the delicacy known as caviare is made. This fish attains a large 

 size, specimens six feet in length and weighing one hundred pounds or 

 more being not uncommon, though of late years they have decreased 

 rapidly in both number and size. 



The spawning season extends from the end of May to the beginning 

 of July, during which period the fish run from the lakes up the rivers for 

 a considerable distance for the purpose of depositing their ova. 



Order RHOMBOGANOIDEA. (The Gar Pikes.) 



Parietals in contact ; pterotic, basis cranii, and anterior vertebrae 

 simple ; symplectics present. Mandible with coronoid, angular, articular 

 and dentary bones ; third superior pharyngeal small, lying on fourth, upper 

 basihyal wanting; maxillary transversely divided. A cartilaginous meso- 

 coracoid. Vertebrae opisthoccelian, that is, connected by ball and socket 

 joints, the concavity in each vertebra being behind. Pectoral fins with 

 mesopterygium and five other basal elements. Tail heterocercal. Air 

 bladder lung-like, single, connecting with the dorsal side of the oesophagus. 



FAMILY LEPISOSTEID^E. (GAR PIKES.) 



Body elongate, subcylindrical, covered with hard, rhombic ganoid 

 scales or plates, which are imbricated in oblique series running downward 

 and backward. Both jaws more or less elongate, spatulate or beak-like, 

 the upper jaw projecting beyond the lower ; premaxillary forming most of 

 the margin of the upper jaw ; the maxillary transversely divided into several 

 pieces. Lower jaw composed of as many pieces as in reptiles ; coronoid 

 present. Both jaws with an outer series of small teeth, followed by one 



