424 SURGEON J. C. THOMPSON ON THE 



the apex and the base. Theie are a few enlarged basal hooks 

 situated close to the sulcus, one being on one side and four on 

 the other ; of these four the one nearest the base is double the 

 size of any of the others. The tip of the organ is rounded and 

 smooth, and the line of demarcation between the bare and the 

 spinous areas is sharp. On either side of the smooth ai-ea at the 

 tip, there are mounted two apical papillae, which are one-fourth 

 the length of the body of the oi'gan. Each papilla is spinous for 

 three-fourths of its circumference, the inner quadrant being 

 smooth and continuous with the spineless area at the tip. 



Terminal papillae similar to those in this species are of com- 

 paratively i-are occurrence. Cope has I'eported them in the genus 

 Oligodon Boie, and in the three following species : Tropidonotits 

 vittatus Linnseus, Ischnogncdhus lineaius ;Hallowell, and Coluber 

 helence Daudin. Each of these has been set apart by Cope as 

 the type of a new genus, established on the groiind that the 

 intromittent organ differed widely from the type prevailing 

 among the nearest allies. T. vihaliciri in this respect is clearly 

 separated from the Far Eastern representatives of the genus. 

 These have been placed in the genus Bothrodytes hy Cope, and 

 are characterized by having the organ furcate. The oi'gan in 

 vibakari most closely resembles that found in Isclmognathus 

 lineatus Hallowell, and the figure given by Cope* of this 

 species shows that it differs from vibalcari in the one detail of 

 being less completely covered with spines. Furthermore, this 

 serpent is of precisely the same mild-actioned and fearless nature 

 that is characteristic of the species of Ischnognathus. In this it 

 offers a marked contrast with the Far Eastern members of the 

 genus Tropidonotiis. Over a dozen species of these have been 

 captured and eveiy one showed a nervous, irritable, and snappy 

 disposition. 



To allow this species to remain in a complex genus like 

 Tropidonotus, after it has been found to differ so radically, is not 

 good taxonomy. On the other hand, to chronicle promptly each 

 new anatomical discovery under a new generic caption does not 

 materially aid our studies. It is believed that the dilemma can 

 be overcome for the time being by strictly adhering to the 

 nomenclature contained in the ' Catalogue of Snakes in the 

 British Museum,' and at the same time by registering a pro- 

 visional new generic term. This new term is not to become 

 current xmtil the entire groiip to which it belongs has been 

 re-examined from the stanrlpoiut of comparative anatomy. 



With this understanding it is suggested that the new genus 

 Hebius be established for Trojyidonotus vihakari Boie, the salient 

 character distinguishing it from all species of Tropidonottbs 

 being the densely spinous and undivided hemipenis, bearing two 

 long apical papillse. 



Helicops avgulaius Linna?us. — The total length of the hemi- 

 penis is 42 mm. ; it is divided into two quadripenes, the length 



* Oj3. cit. pi. xx. fig. 12. 



