28 Dr. Dawson on Stromatopora as 



teeth of the outer series are visibly stronger than the remain- 

 der. Barbel shorter than the eye. The interorbital space is 

 flat, its width being equal to the diameter of the eye, which is 

 comparatively large. The scales are provided with five 

 ridges, each ridge composed of several small spines, and the 

 central ridge being the strongest. There are eight scales in 

 a transverse series between the first dorsal and the lateral line. 

 Prseoperculum with the posterior margin slightly excised 

 above the angle, and with the lower margin crenulate ; both 

 limbs of the prseoperculum scaly. The second dorsal spine is 

 armed with barbs which are rather closely set. The second 

 dorsal fin commences at a distance from the first which is not 

 much more than one half of the length of the head. 



Deep sea, east of the mouth of the Rio Plata (Station 323) , 

 1900 fathoms. 



Coryphoinotdes carinatus. 



Snout obtusely conical, projecting beyond the mouth, the 

 cleft of which reaches nearly to below the middle of the eye. 

 Teeth in the upper jaw "■ en cardes," those in the lower in a 

 single series. Barbel well developed, but much shorter than 

 the eye. Interorbital space flat, much narrower than the 

 large eye, the diameter of which equals the length of the 

 snout. The scales are provided with a very strong median 

 keel, terminating in a projecting spine, and with several sliort 

 and low ridges, which converge towards the median keel or 

 run nearly parallel to it. There are six scales in a transverse 

 series between the first dorsal and the lateral line. Prajoper- 

 culum with hind margin undulated and with limbs scaly. 

 The second dorsal spine is armed with rather small and some~ 

 what closely set barbs. The distance between the two dorsal 

 fins equals the length of the base of the first. 



Deep sea near Prince Edward's Island (Station 145), 500 

 fathoms. 



[To be continued.] 



III. — Stromatopora as distinguished from Millepora. 

 By Dr. Dawson, F.R.S. &c. 



The April number of the ' Annals ' reached me not long after 

 the completion of a series of careful microscopic studies of the 

 Stroinatopoi'ce and allied forms, which abound in all our 

 American formations from the Black-River Limestone to the 

 Corniferous Limestone inclusive, and in which I had en- 



