102 MR J. T. CUNNINGHAM ON THE 



This temperature was fatal to a large number of the developing eggs. The 

 temperature of the water in which the eggs were first placed was 12°5 C. With 

 these great variations in temperature, hatching took place on the sixth day. 

 The larva is not different from that of the other species of Pleuronectes ; its 

 length is 3*9 mm.; there is no pigment in the eye ; a number of very minute 

 pigment spots are scattered down the sides. The anus is not open, and the 

 coalesced segmental ducts do not communicate with the rectum (see PL V. fig. 5). 

 PL V. fig. 7, shows the condition of the larva a little more than forty-eight 

 hours after hatching. The length is now increased to 5 9 mm. — a very rapid 

 rate of growth. The median fin-fold is much wider. The eye is slightly 

 pigmented, and pigment is largely developed in the skin of the body. The 

 cutaneous chromatophores form five well-marked transverse stripes, arranged 

 in longitudinal series along the sides, three of them on the tail, one in the 

 region of the rectum, and one about the pectoral fin. No trace of the pelvic 

 fin is to 'be seen. The operculum is present as a slight fold, and beneath it 

 the first branchial cleft is widely open; behind this are four clefts indicated but 

 not perforated. The mouth is also still wanting. 



7. Pleuronectes microcephalics (Lemon Sole). 



I have not obtained fertilised ova of this species, but I was able to ascertain 

 from examination of unfertilised mature examples that there are no oil globules, 

 and that the diameter measures 1*1 mm. The ripe females, from which the 

 mature eggs came, were taken in the trawl east of May Island, May 22 of the 

 current year. 



8. Gadus wglefinus, Linn. (Haddock) (PL VI. fig. 1). 



The ova of Gadus morrhua, G. wglefinus, and G. merlangus, in various 

 stages of development, have been previously figured by me.'" The larvae, after 

 hatching, were not described in the paper I refer to. The newly hatched cod 

 has been correctly figured by John EYDER.t For the sake of comparison, I 

 give a figure of the newly hatched larva of the haddock. The eye is pigmented, 

 and there is a single row of dendritic chromatophores along each side ven- 

 trally. The anus is not open, nor the mouth ; the pelvic fin is also wanting. 

 In all respects, except in size, the larva of the haddock resembles that of 

 the cod. 



The following species of ova and larvae were not obtained directly from the 

 parent fish, but identified from other considerations. 



"Relations of Yolk to Gastrula in Teleosteans," Quart. Jour. Mia: Sci., 1885. 

 t Report of American Fish Commission for 1882, Washington, 1884. 



