202 
Young Stages of Zeugopterus punctatus. 
By 
J. VT. Cunningham, M.A.. 
Naturalist to the Association. 
On May 4th of the current year a number of small Pleuronectids 
were captured by the hand in a pool left by the ebb tide at Plymouth 
Breakwater, and brought to me alive. Two of them were very 
transparent, and, from their habit of lying on the right side when at 
rest, evidently sinistral forms. One of them was almost perfectly 
symmetrical ; while in the other the torsion of the facial region and 
eyes had commenced. ‘The pigmentation had the form of inter- 
rupted transverse bands, which were most conspicuous on the dorsal 
and ventral fins; on the dorsal fin seven bands were indicated. 
The terminal portion of the original trunk, containing the notochord, 
was seen at the upper edge of the caudal fin. The neurochord was 
covered with pigment, forming a very distinct band, situated, how- 
ever, not in the skin, but in the connective tissue surrounding the 
neurochord or spinal cord. The mouth was large, and the snout up- 
turned. The pectoral fin was large, the pelvic small. But the most 
important characteristic was the presence of two straight spines pro- 
jecting laterally from the auditory region. These have been called 
otocystic spines by Prof. McIntosh, but I think they would be more 
appropriately described as periotic spines, as they are evidently pro- 
jections of the periotic cartilage or bone; to which particular bones 
of the periotic region they belong has not been determined. 
Mr. Holt cut sections of the spines in situ, and found that they 
consisted of a knob of periotic cartilage passing into a mass of 
undifferentiated cells, the whole forming the core of a dermal spine 
consisting of hyaline ossified tissue. In my specimens I observed a 
third spine, much smaller, situated in the region of the frontal bone, 
behind and above the eye ; it was visible in both the stages. 
The numbers of the fin-rays were D. 90, A. 69, in one specimen, 
which was kept alive for a few days and preserved when the right 
