1894.] -^1' [Cope. 



where the former cannot be employed. For coordination of series in two 

 distant places between which there is no stratigraphical connecliou, 

 paleontological evidence is the only evidence available. 



On the Lungs of the Qphidia. 

 By Prof. E. D. Cope. 



(Read before the American Philosophical Society, May IS, IS94.) 



The condition of knowledge as to the characters of the lungs of snakes 

 was stated by Stannius, in 1856,* as follows: "The detailed accounts 

 as to the single or double character of the lungs leave much to be desired. 

 Among Opliidia Angiostomata there possess a single sack, Rhiuophis and 

 all Typhloi)idie which have been examined ; as to the Tortricidaj [llysi- 

 idae], there are apparently species with two lungs (2'. xenopeltis) [= Xen- 

 opeltis unicolor'\, and others with a single lung {T. scytale) [:= Ilysia scy- 

 talel- Among Eurystomata, all the Peropoda (Boa, Python, Eryx) 

 possess apparently tvvo lungs. The Calamariua that have been investi- 

 gated have one lung. Among Colubrina and Glyphodonta, there are 

 great variations. All the Coronella? of Schlegel possess, according to 

 Schlegel, a single lung. I find the lung single in lihachiodon scaber 

 [Dasypeltis]. 2'ropidonottis natrix \_Natrix vulgaris] has a very small 

 rudiment of a second lung. Coluber [Spilotes'] variabilis possesses, 

 according to Schlegel, the rudiment of a second lung. According to the 

 statement of Meckel, this rudiment is common in Coluber. The Xeno- 

 dons have, according to Schlegel, a single lung (X secerns and X. rliabdo- 

 cephalus). In Heterodon I find a rudimental second lung. The Lyco- 

 dons, according to Schlegel, possess a single lung ; as also do Psammophis 

 and Homalopsis. In Dtndrophis colubrina Schlegel found the rudiment 

 of the second lung. In Dipsas, according to Schlegel, there are varia- 

 tions ; but he states that 1). muliimaculata, D. Icevis and D. annulata 

 [Sibon annulatum], have but one lung. The Achrocbordina have but 

 one lung. Among Hydrophidaj I found in three species of Hydrophis the 

 lung-sack simple. Meckel states that Platurus has a very small rudiment 

 of a second lung. Among the remaining poisonous snakes there is an 

 insignificant rudiment of the second lung in the Elapina and Crotalina ; 

 while the Viperina possess an entirely simple lung." 



The absence of tangible external characters which furnish indications 

 of affinity in the Ophidia is well known. The important characters to be 

 found in the skeleton were mostly pointed out by Miiller, and Dumeril 

 and Bibron examined and utilized the characters of the dentition. The 



* Zootomie der Amphibien, p. 108. 



