280 LOWER VERTEBRATES. 



The spawning season is " late in tlie year and during the sirring months." The ova 

 are in moderate number ; a sole of one pound weight has, according to Buckland, 

 about 134,000 eggs. The newly-hatched, according to Dr. Day, do not appear to be 

 commonly found so far out at sea as some other species. They enter into shallow 

 water at the edge of the tide, and are very numerous in favorable localities. 



As is well known, the sole is one of the most esteemed of European fishes. In 

 the words of Dr. Day, " the flesh of this fish is white, firm, and of excellent flavor, 

 those from the deepest waters being generally jjref erred." "Those on the west coast 

 and to the south are larger as a rule than those towards the north " of the British 

 islands. In addition to its use as food, it is available for another purpose. The skin 

 is used for " fining coffee, being a good substitute for isinglass," and also as " a material 

 for artificial baits." 



The markets are generally supplied by the trawl. "The principal English trawl- 

 ing ground lies from Dover to Devonshire. They may be taken by spillers, but are 

 not commonly captured with hooks ; it is suggested that one reason may be that 

 spillers are mostly used by day, whereas the sole is a night feeder." They are some- 

 times angled for with the hook, baited with crabs, woi'ms, or molluscs; the most fav- 

 orable time for fishing is at night, "after a blo*v, when the water is thick, while a land 

 breeze answers better than a sea breeze." 



The nearest American relative of the sole is a shorter fish destitute of pectorals, 

 for which reason it has been named Achirus lineatus. It is a worthless animal, as one 

 of its popular names — hog-choker — suggests. The name sole is misapplied on the 

 Pacific coast to several true Pleuronectids. 



Order VIII. — HEMIBRANCHII. 



The well-known sticklebacks are the most faiuiliar representatives of another 

 order of true fishes. Although the external appearance may not excite suspicion of 

 essential distinction from the ordinary Acanthopterygians, an examination of the skel- 

 eton reveals differences that have been regarded as of ordinal value. The shoulder- 

 girdle does not have two bones, as usual, connecting the larger one with the cranium, 

 but a single one connects the proscapula, or largest bone of the shoulder-girdle, with 

 the skull. In addition to this, the pharyngeal bones and branchial arches generally 

 are reduced, and some elements deficient. It is to this imperfection of the branchial 

 apparatus that the ordinal name — Hemibranchii — alludes. Six families are recog- 

 nizable for the living rejjresentatives of the order. 



The Gasterosteid^ are hemibranchs with the body more or less fusiform and 

 elongate ; the sides naked, or covered with a more or less extended row of vertical 

 shields, and the head acute or produced into an almost tubiform snout ; the back is 

 armed with stout, pointed spines ; the ventrals are sub-thoracic, and each has a spine 

 and one or two rays. Stickleback is a general name, alluding to the strong dorsal 

 spines, for all the forms of the family Gasterosteidse, but numerous other names are 

 given. 



The species are confined to the northern hemisphere, and are all of small size, and 

 some are very minute, and among the smallest of fishes. In Europe three genera occur, 

 one almost confined to the sea and the others indifferently inhabiting salt and fresh 

 water. In the United States four genera are developed, two brackish water ones in 

 common with Europe, and two peculiar to the United States and quite distinct from 



