The Embryology of Heterodontus japonicus 677 



There remains some doubt concerning the identity of a Heterodontid shark taken off 

 the western coast of Mexico, or perhaps of Central America, which was described and 

 figured by Kumada and Hiyama (1937)- They named it Gyropleurodus perua7%us. Their 

 drawing portrays a shark in most respects like H. quoyi, but the color pattern is inter- 

 mediate between H. quoyi and H. francisci. Since the color pattern of the former is 

 somewhat variable, the drawing was probably made from a specimen of H. quoyi; but 

 there is no other record of the occurrence of this species so far north. 



Heterodontus quoyi was first figured and described by Freminville (1840); and later 

 by Valenciennes (1846 and 1855). Their figures are based on the same specimen, a male 

 taken at the Galapagos Islands; but these differ so much that they might be considered 

 as representing two different species. Valenciennes called this specimen Cestracion 

 pantherinus, though it had been previously named Cestracion quoyi by Freminville. The 

 brief accounts by Dumeril (1865), Gvinther (1870), Maclay and Macleay (1879) are based 

 on either Freminville's or Valenciennes' description and figure; they contain nothing 

 new. Maclay and Macleay's figure (1879) is a copy of Freminville's. Until Carman 

 (1913) described at least one new specimen (a female taken at the Calapagos Islands), 

 Freminville's male specimen of H. quoyi remained the only example of the species. In 

 his very inadequate description, some comparisons with Heterodontus phillipi are 

 irrelevant since they involve the acceptance of erroneous features in Lesson's (1826) 

 drawing of the Port Jackson Shark. Freminville's figure of H. quoyi does not inspire 

 confidence, and I have therefore reproduced Valenciennes' life-like portrait of the same 

 specimen (my Text-figure 16) as the basis of this account. 



The length of Freminville's specimen is variously recorded as a little more than 

 a foot and a half, by Freminville; 475 mm. (18.7 inches) by Valenciennes; 460 mm. (18.1 

 inches) by Dumeril; and two feet (evidently a blunder) by Maclay and Macleay. Car- 

 man's female specimen measured 18 inches long. Carman states that its body is rather 

 stout as compared with a specimen of H. zebra of equal length. Some passages in Carman's 

 characterization imply that he had more than one specimen, but he does not give the 

 lengths of any others. 



The most noteworthy feature of Freminville's drawing of H. quoyi is the small size 

 of the head. The author states that the head is smaller and a little more elongate than 

 that of Cestracion phillipi. As portrayed by Freminville, the head is very small and 

 pointed. In Valenciennes' drawing (my Text-figure 16) the head is proportionally much 

 larger. Carman does not say that the head of his specimen (or specimens?) is small. He 

 does write that the snout is blunt, the cheeks swollen, the eye and spiracle small. Fremin- 

 ville states that the supraorbital ridge is comparatively weak ("moins forte") but Carman 

 records that it is strong, somewhat overhanging the orbit, not ending abruptly as in H. 

 francisci. In Valenciennes' figure (my Text-figure 16) the posterior extremity of the 

 supraorbital ridge ends rather abruptly, as in Kumada and Hiyama's figure of H. francisci 

 (my Text-figure 18, page 682). Some specimens of H. quoyi examined by me show vari- 

 ations in the form of the supraorbital ridge, as described later. 



