306 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 48. 



RAJA INORNATA Jordan and Gilbert. 



Station 4452, Monterey Bay, 49-50 fathoms. 



An embryo in the egg case with yolk about two- thirds absorbed, 

 and a young specimen 180 mm. long were secured from this station. 



In the embryo, the contour of the snout is very broadly rounded, 

 the extreme tip abruptly protruding. None of the spines are yet 

 free but the primary spines can be made out recumbent beneath 

 the integument. Two in front of eye and one on posterior superior 

 orbital rim are evident. And on the median line of back, an un- 

 broken series extends from the posterior edge of branchial area to the 

 first dorsal fin. The anterior three of these are hard and spinous, 

 and longer than those which follow, the third somewhat weaker 

 than the first two. The fourth and fifth are small, weak, and flexible, 

 and the remainder of the series are hard and spinous, though smaller 

 than the anterior three. In the freshly hatched young the three 

 primary ocular spines appear and are for a time the only spines pres- 

 ent on the orbital margin. Later, the number is increased through 

 the intercalation of secondary spines. 



We have no postembryonic specimens showing an uninterrupted 

 series along back. The first three typically appear, though occa- 

 sionally only the first two are present, then follows an interval where 

 were found in the embryo the rudiments of two or three weaker 

 spines; and finally, beginning opposite the anterior ventral lobe, the 

 remainder of the series. It is not known whether the weak fourth 

 and fifth spines of the series fail to break through or whether after 

 doing so they retrograde. 



RAJA RHINA Jordan and Gilbert. 



List of stations. 



4365 

 4452 



Near San Diego. 

 Monterey Bay . . 



Fathoms. 



130-158 



49- 50 



Three young specimens, 170 to 225 mm. long. 



As stated by Starks, 1 the young of R. inornata and R. rhina are 

 difficult to separate, as the characteristic form of the disk in R. rhina 

 has not yet developed, and the spines and color are then very similar. 

 A difference in the primary spines seems, however, constant and 

 diagnostic. In our youngest specimens the orbital spines are dis- 

 tinctly larger than in R. inornata, and the anterior of the median dor- 

 sal series is always very strong and single, a wide gap separating it 

 from the succeeding spines of the series. In R. inornata the anterior 

 dorsal spines are smaller and are always present in a series of three (or 

 rarely two) . There are in this collection no embryos of R. rhina which 



i Ann. Carnegie Mus., vol. 7, 1911, p. 172. 



