LARVAL AND POST-LAKVAL TELEOSTEANS. 365 



obtained the newly hatched larva at a length of 4-1 mm., but its appear- 

 ance was entirely different from HeiTord's specimen. The distinguishing- 

 feature was a well-marked pre-cephalic expansion of the dorsal fin mem- 

 brane. It was taken much later in the year, and thus more in agreement 

 with the known spawning period than HefEord's larva. My earliest post- 

 larvae have all got this peculiar " hooded " structure, though much less pro- 

 nounced. There is distinct evidence in my specimens of shrinkage in this 

 region, so that there seems to be grounds for believing that this pre-cephalic 

 structure was indeed larger in the larval state. I am inclined to consider 

 Hefford's larva, though not without great reservation, as belonging to 

 another species, possibly S. variegata. The pigmentation, shape of head, 

 depth of body, more backward position of the anus, and length of the 

 specimen seem to agree more nearly with the characters of S. variegata. 

 I have described and figured post-larval stages from 5 025 to 11-25 mm. 

 The rate of growth seems rather unequal, and considerable variation 

 is apparent. The metamorphosed specimen of 11-25 mm., though far 

 from having completed its post-larval growth, represents perhaps the 

 minimum length for such an advanced stage, as in specimens of 11-5 mrn., 

 the left eye has not even reached the dorsal margin. 



S. lascaris Kisso. 



Fig. 5. Length 5-025 mm. 



Length 5-025 mm., of which 3-4 mm. are post-anal. The preanal length 

 is about 2| times in the total, so that the anus is well in front of the 

 middle of the body. The snout is slightly longer than the diameter of 

 the eye. The lower jaw projects beyond the upper. The greatest 

 depth, which is measured over the middle of the abdominal region, 

 is slightly under three times in the total length. The development 

 of the fin rays is suggested posteriorly by the arrangement of the 

 dorsal and anal pigment. Hypural rays are developed. The verte- 

 brae have not advanced sufficiently to be counted. The snout is 

 compressed and notched where it receives the dorsal fin membrane. 

 The membrane curves back half-way over the nasal region and 

 parallel to it, and then rises almost vertically, giving the larva a 

 " hooded " appearance. This feature is quite distinctive of S. lascaris, 

 and reminds one of Holt's newly hatched (4-1 mm.) larva of the same 

 species with its " abnormal " development of this region. The mid- 

 brain is prominent ; it overlies the orbit and its anterior outline is almost 

 parallel to the anterior dorsal fin margin. The ej^es are perfectly sym- 



