122 MR J. T. CUNNINGHAM ON THE 



night. The ovum measures ^§ to £$ mcu m diameter, or, as measured from the 

 figures given, '856 to 1*06 mm. It is pelagic; there is a single large oil 

 globule, otherwise the yolk is homogeneous ; the perivitelline space is small. 

 The newly hatched larva is 2-52 mm. long as measured from the figure ; the 

 notochord is multicolumnar ; the anus immediately behind the yolk, and open ; 

 pigments spots are present on the body and round the oil globule, and 

 also form one conspicuous transverse stripe in the middle of the tail. The oil 

 globule in the hatched larva is situated on the ventral side of the yolk, a little 

 posteriorly. The mouth opens twenty-one hours after hatching. 



Fam. 8. Trachinid^;. 



The development of Tracliinus vipera has been described by Geo. Brook 

 {Lin. Soc. Jour., vol. xviii., 1884). The eggs were shed in that author's 

 aquarium. Spawning takes place at night, and is continued through the 

 months of May, June, and July. The ovum is pelagic, 1 32 mm. in diameter, 

 and contains from 20 to 30 small oil globules. The oil globules are external to 

 the vitellus, and contained in depressions of its surface. It is probable that this 

 is often the case ; it certainly is in Trigla gurnardus, but whether the oil 

 globules are always external is doubtful. The perivitelline space is small. 

 Hatching took place on ninth, tenth, and eleventh clays, at a temperature of 54° 

 to 60° Fahr. In the newly hatched larva the rectum is immediately behind the 

 yolk sac, the notochord multicolumnar. The eyes are pigmented; black pig- 

 ment cells are scattered over the body and the surface of the yolk sac, and 

 aggregated in a transverse stripe at the middle of the tail. The ventral fins are 

 well developed at the time of hatching. The length of the newly hatched larva 

 is 3 5 mm. The yolk sac is absorbed, and the mouth well developed twenty- 

 four hours after hatching. 



Fam. 9. Batrachid^:. 



The young Batrachus tau, Lin., 2 mm. in length, has been figured by 

 Storer (Mem. Amer. Acad., v. pi. xix.). Agassiz figures a specimen 6 mm. 

 in length in Young Stages, pt. iii., but this shows only traces of the larval 

 characters. The anal is still continuous with the caudal fin, and the " ganoid " 

 lobe of the tail is well marked. 



Fam. 10. Pediculati. 



The eggs of Lophius piscatorius, Lin., are described in Young Stages, pi. 

 iii. The eggs are held together by gelatinous mucus in a single flat layer 

 which floats horizontally in the sea, forming a large sheet 3 feet broad and 

 'I") to 30 feet long. The spawn is shed on the American coast from June to 



