1897.] NEW YORK ACADEMY OF SCIENCES. 369 



protamin nucleate, having the formula C4oHg4Ni4P4027, 

 CgoH^^N^^Og. Nucleinic appeared identical with that of salmon 

 sperin (Meischer), although the protamin differed from salmon 

 protamin as shown by Kossel. The sperm tails consisted chiefly 

 of a combination of lecithin, cholesterin, and albumen similar to, 

 but not identical with, similar constituents of salmon sperm tail. 

 The tails contain no nuclein. The heads contain no lecithin nor 

 cholesterin. Arbacia sperm contained nucleinic acid, but no 

 protamin. Instead of this a histon-like body. It is probable 

 that arbacia sperm chromatin is histon nucleate and more com- 

 plex than fish sperm chromatin. Neither bull nor pig sperm 

 contain protamin. The author suggests that simplicity of fish 

 sperm chromatin is difficult to reconcile with Weisman's hypo- 

 thesis. 



Dr. Bashford Dean, in "Notes on PaljBOspondylus," gave a 

 brief reply to Dr. Traquair's recent objections (Pro. Zool. Soc. 

 Lond., March IG, 1897). The author notes : 



1. That the radial-shaped markings of the type specimen are 

 certainly part of the fossil, since the}^ occur in a second specimen 

 now in the possession of Professor Stratford. 



2. That his (Dean's) broader interpretation of the " impaired 

 nasal opening '" (Traquair) as a naso-mouth ring (as in Myxine) 

 was an independent as well as a necessary one, as will appear in 

 the full paper. 



3. That the view of the presence of the radial-shaped mark- 

 ings, as the probable basal supports of paired fins, the relations 

 of Palseospondylus to the Marsipobranchs become even more 

 hypothetical. 



Dr. Matthew, in speaking of the fauna of the Puerco Basin, 

 showed that the form Ilixodectes, formerly supposed to be a 

 primate allied to the modern Ghiromys, is a true rodent in the 

 first stage of evolution. It has the characteristic rodent astraga- 

 lus, very like that of the earlier sciuromorphs. The incisor is 

 intermediate between the short, rooted, spatulate incisor of most 

 modern mammals and the long, rootless scalpriform incisor of the 

 Rodentia. The root is long, but does not grow from a persistent 



Tkansactions N. Y. Acad. Sci., Vol. XVI., Sig. 24, March 11, 1898. 



