EGGS AND LARY^ OF TELEOSTEANS. 109 



the eggs and larvse, then to ascertain what features are common to all the 

 families of the order, and finally to compare the characters which belong to the 

 several orders. We shall take the families as denned by Gunther in the 

 article " Ichthyology" of the Encyclopaedia Britannica. 



Fam. 1. SiluriDjE. 



The female of Aspredo batrachus attaches the eggs to the skin of her own 

 ventral surface, and carries them about there until they are hatched. The 

 male Arius carries the eggs about in his pharynx. The male Callichthys 

 makes a nest. 



An account of the breeding and development of Amiurus albidus (Lesueur), 

 Gill, is given by John A. Ryder in Bull. U.S. Fish. Com., vol. iii. The ovum 

 is adhesive, and ^ inch in diameter after fertilisation ; the vitellus was \ inch 

 in diameter. The female deposited the whole of her eggs at one time in a 

 tank, in one mass, which was 6 inches in length by 4 in width, by § inch in 

 thickness. The male watched over the mass with great assiduity till hatching- 

 occurred, and constantly fanned the eggs with his anal, ventral, and pectoral 

 fins. The perivitelline space in the develoj>ing ovum was crowded with free 

 refringent corpuscles, a fact not noted in any other Teleostean ovum. Hatch- 

 ing took place on sixth to eighth day. The intestine in the larva ends not very 

 far behind the yolk sac. 



Fam. 2. Scopelid^e. 

 „ 3. Cyprinid^e. 



The carps are all fresh-water fishes. The eggs are in most cases adhesive, 

 and attached to aquatic plants. The zona radiata is double. Carassius 

 auratus, L., the gold-fish, and the variety known as the telescope-fish, 

 attach their eggs to water plants (M. von. Kowaleswki, Zeit. f. iviss. Zool., 

 Bd. xliii.). 



The larvae of Cyprinus (Leuciscus) rutilus and C. idus are figured by 

 Sundevall. These figures are curious. In the newly hatched larva they show 

 the yolk apparently extending back to the anus ; that is to say, although the 

 anus is near the end of the tail, as in other physostomous larvse, the yolk, 

 instead of being ellipsoidal in shape, is elongated, and occupies, in addition to 

 its usual space, the interval ordinarily taken up by the preanal median fin-fold. 

 The latter structure is shown in a normal state of development in stages sub- 

 sequent to the absorption of the yolk, and it is possible that the apparent 

 anomaly in the earlier stages is due to want of definition in the drawings, as 

 in Sundev all's figures generally the limit between intestine and yolk sac is 



