130 THE SEA-SCORPION FAMILY. 



been drawn upon for the present purpose. The eggs are found 

 between tide-marks in April amongst tufts of sea-weed, or on 

 ledges of rocks, so as to be partially exposed at low water. The 

 masses are usually flattened, and of a size less than the palm 

 of the hand. The diameter of the egg is 1'70 to TSS mm. The 

 capsule is peculiarly corrugated or minutely nodulated, and the 

 yolk has a golden yellow or straw-colour. The oil-globules are 

 numerous, as shown in the figure. 



The newly hatched larva (Plate V, fig. 9) is smaller than 

 that of the short-spined bull-head, measuring about 5'7 mm. 

 The choroidal pigment of the eye has a deep blue colour 

 (Cunningham). Yellow pigment occurs on the head and the 

 pectoral region. No black pigment exists on the top of the 

 head, or along the ventral edge behind the vent. The pigment 

 along the roof of the abdomen is peculiarly dark, and has quite 

 a different aspect from that of the species above mentioned. 

 Mr Holt has likewise pointed out that the circulation of the 

 yolk-sac is more complex than in the other species, the blood 

 leaving the liver in at least two and generally in three vessels. 

 The oil-globule lies behind the heart in front and has a diameter 

 of '22 mm. 



In two days the length in confinement has increased to 6 mm., 

 and the yolk is reduced. Black chromatophores occur along 

 the edge behind the vent, which is open, and canary-yellow 

 pigment amongst the black on the I'oof of the belly. On the 

 fourth day embryonic rays appear in the tail-fin ; the length is 

 ri-28 mm., and the oil-globule i.'^ reduced. On the sixth day the 

 yolk is still further diminished. Black corpuscles have appeai-ed 

 in the covering of the mid-brain, internal to the ear-capsules 

 and round the vent. The gills show papillae. At the tenth 

 day the length reaches 642 mm., chiefly from increase in the 

 tail, the jaws move freely, an opercular fold is present, and the 

 gills are pectinate. The livei' is much larger. Black chromato- 

 phores form a conspicuous median dorsal line over the anterior 

 part of the abdomen, and similar pigment appears on the 

 pre-anal fin. 



At the 20th da}' in confinement, increase in length was 

 found by Mr Holt to be iri/, probably from want of food. All 



