114 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.xxh. 



would decide the question on which the authorities disagreed, as shown 

 in the last sentence quoted from the above paper. 



It would appear an easy matter to place this form under one or the 

 other of two families arranged in different suborders, as the Sphyrsen- 

 idse and Oheilodii^teridae usually are: but the fact that two of the 

 authorities consider it under one family and two under the other, indi- 

 cates how close the resemblance must be to either. 



Sphyrmna argentea is the form chosen to represent the family Sphy- 

 rsenidse, while the only representative procurable of the Oheilodipter- 

 idse was Apogon maculatiis. 



The skeleton of Apogon was found to be of but little assistance in this 

 comparison. Though being undoubtedly Percoid, it differs as much 

 from Dinolestes as they both differ from the more generalized Percoids, 

 such as the bass or perch. Considering the difference between Dino- 

 lestes and Apogon in external appearance, we have probably little reason 

 to expect the internal resemblance to be otherwise. Perhaps if one of 

 the 8p]iyrwna-]ike Oheilodipteroids could be examined there would be 

 a closer resemblance. 



To be sure Dinolestes differs from Apogon only in shape and compar- 

 ative size of elements (that is, comparative between corresponding 

 elements of each species), and not in arrangement, or lack or posses- 

 sion of elements; but it is so very different in shape of cranium, form 

 of body, and shape of fins that it would seem better to consider the 

 Cheilodipteroid side of the question partly by considering the Percoid 

 fishes more or less as a whole. Though, of course, if it is ijlaced with 

 the Percoids it is only under the family Oheilodipteridse, as the Per- 

 coids are now arranged, that Dinolestes could be admitted. 



Were it not that the ventrals oi Dinolestes are apparently thoracic, it 

 might appear after a superficial external examination to be related to 

 Sphyrcena. The long head, projecting lower jaw, fanglike teeth, and 

 elongate preorbital region are very Sphyrcenalike. Q'he shape of the 

 body and dorsal fins are also suggestive of that relationship. 



In internal characters we find that the ethmoid is wide and flat, some- 

 what overlying the vomer and prefrontals instead of being interposed 

 between them. Tbis is the condition found in iSphyrcena. The nasals 

 are very much like those of Sphyrcena, being long and channeled and 

 attached by their sides to the ethmoid for nearly their whole length. 

 This, however, is probably caused by the elongate snout, and goes with 

 it as a part in keeping with the surrounding conditions. It disposes of 

 the characters by which an alliance with Sphyrcena covtM be proved. 



Though the shajDC of the body and head, the canine teeth, and dorsal 

 fins exhibit perhaps a closer superficial resemblance to the Sphyraenidse 

 than to the Cheilodipteridiie, there are forms to be found in the latter 

 family which approach this Sphyrcena-like appearance also. These 

 characters therefore denote nothing in favor of either relationship. 

 The characters of the ethmoid and nasals are the only characters pos- 

 sessed by Sphyrcena in common with Dinolestes that are not also shared 



