830 PROFESSOR W. C. M'INTOSH AND MR E. E. PRINCE ON 



anterior end of the mandible as well as on the summit of the head black spots occur. A 

 most striking feature is the extraordinary length of the ventral fins (vf), three of the fin- 

 rays in each being very long, while the fourth is shorter. The fins are of an ochre-yellow 

 colour along the rays, with specks of black pigment scattered over the inter-radial mem- 

 brane. The iris, like that of the eye of the whiting, is of a pale sky-blue. The notochord 

 passes almost in a straight line backward to the tip of the tail, and the caudal fin is con- 

 tinuous with the unbroken marginal fin dorsally and ventrally. The great development 

 of the ventral or permanent rays, however, slightly pushes the tip with the embryonic 

 radial striations upward. The hypurals, two of which are very distinct, are developing 

 inferiorly, and the epiurals dorsally, but they have only slightly affected the direction of 

 the notochord. The early development of the upper caudal rays in this form is of interest, 

 as it is in marked contrast with such forms as the Pleuronectidae in which the inferior fin- 

 rays alone appear. 



The head and the eyes are disproportionately large, and the prominence of the 

 hyomandibular apparatus, as well as the size of the mandible, gives to the jaws a massive 

 character, just as in the cod. The angle of the jaw is especially marked, projecting 

 prominently inferiorly — rather behind a vertical line drawn from the centre of the lens. 

 The hyoidean apparatus, and subsequently the whole facies, the opercular structures, and 

 branchiostegal rays, are remarkably developed. The pectorals (pf) have short fleshy 

 bases with fan-like expansions of fin-rays of moderate length, not unlike the condition in 

 the adult. The barbel can barely be distinguished. The alimentary canal has a com- 

 paratively simple course, the capacious stomach bending to the right, whence a wide and 

 straight intestine passes backward nearly to the anus, then bends forward, doubling again 

 behind the stomach on the left side, before proceeding straight to the anal opening. 



The next observed (on 21st July 1887) was about 15 mm. in length, three occurring 

 in the mid- water net in a haul at 22 fathoms. The pigment and other characters of 

 these do not require special mention. The yellow pigment is at once removed by 

 alcohol, but the black remains. 



On 31st August 1886 examples of the next older stage (PI. XVIII. fig. 4) were 

 obtained off the Isle of May. The dorsum again was greenish, and a similar pale tint 

 existed over the trunk and tail, while along the sides of the latter black pigment occurred. 

 The long ventrals extended more than one-quarter the length of the body, three rays 

 being especially distinguishable for their size, while three rudimentary rays were present 

 at the base. Their colour is similar to that of the last stage. The pigment of the 

 body, especially that of the two black bars above described, is now more diffuse and 

 continuous, the bars being however indicated by two isolated dorsal bands. The 

 blackish pigment in front of the ventrals is more definite, forming a broad arrow or 

 A-shaped figure, and at the tip of the mandible, on each side of the symphysis, a band 

 occurs, and a trace also is distinguishable in front of the barbel. Dorsally, a slender 

 stripe exists along the premaxillse, and the pigment on the cranium is better defined. 

 All these external features were, however, already indicated in the yo\mger examples. 



