HOLDEX. — CRETACEOUS PITYOXYLA. G21 



SUMMARY. 



1. The Pityoxyla of Cliffwood, New Jersey, include the following 

 previously undescribed varieties : 



(1) Piiius proto.'tclrropifj/s, — probably the earliest form with all 

 the characters of a modern hard pine, yet retaining certain 

 ancestral features, as the association of primary and fascicular 

 leaves, the latter borne on brachyblasts subtended by a foliar 

 trace. 



(2) Pifj/oxt/lon foliosum , — possibly the wood of Pre pin us, with all 

 its lea\"os borne directly on the main axis, and presenting mingled 

 characteristics now confined exclusively to either hard or soft 

 pines. 



(3) Pitijoxylon anomahnn, — with ligneous features extremely like 

 those of Prepinus, yet with all its leaves borne on short shoots. 



2. The absence of tangential pitting in the first described Pity- 

 oxyIo)i, and its presence in the other two, confirm the conclusions 

 of Jeffrey and Chrysler that tangential pitting is a primitive 

 feature now lost in the more highly specialized hard pines. 



3. The absence of evidence confirming th6 origin of ray tracheides 

 from vertical tracheides of the wood, renders it unlikely that this 

 hypothesis is correct. 



4. The occurrence of a completely differentiated hard pine as far- 



back as the ^Middle Cretaceous is an argument for the great 

 geological antic^uity of the pines as such. 



In conclusion, I wish to thank Professor E. C. Jeffrey for all the 

 material used in this investigation, for an opportunity to examine 

 sections of Prepinus, and for his helpful advice throughout the 

 course of the work. To Professor I. W. Bailey, I am indebted for 

 opportunity to study sections of Piniis scitiiatensiformis, and to Mr. 

 E. W. Sinnott for sections of various living pines. 



