Mr. G. A. Boulenger on new 8j)ecies of Geckos. 473 



ture follows the outline or intervals of the disks and plates. 

 The shell appears to be silicious and remains unchanged when 

 exposed to the action of heated sulphuric and nitric acids." — 

 Oj). cit. p. 151. 



The encystation of the naked and testaceous Amoebans, 

 the process of " coagulation " and " consolidation " of the 

 ectosarc by which the membranous structure of the en- 

 cysting sac is produced, the formation of the diaphragm 

 by which the mouth of the testaceous Amoebans is closed 

 during their encystation, and the characters each of these 

 parts assume, will be found described by me in the ' Annals ' 

 for May 1863, pp. 367 to 369; 'Annals,' Nov. 1863, 

 p. 336 J 'Annals,' Dec. 1863, p. 462; and ' Annals,' March 

 1864, p. 235. 



It only remains for me to say that more admirably and 

 truthfully executed figures of the freshwater Rhizopods 

 have never been issued than those contained in Prof. 

 Leidy's work. In no other publication have such indisputable 

 proofs ever been brought together of the process of natural 

 evolution from one end to the other of a very extensive and 

 complete series of Protozoan organisms. Had Prof. Leidy 

 dwelt somewhat more fully and distinctly than he has done 

 on this the most striking feature in his researches he would 

 indeed have conferred benefits of no ordinary magnitude upon 

 the branch of science of which he is so distinguished an 

 expositor*. 



XLIII. — Descriptions of three new Species o/" Geckos. 

 By G. A. Boulenger. 



Gecko pumilus, sp. n. 



In habit similar to Lepidodactylus Guppyi. Head small, 

 body elongate, limbs moderate. Snout once and one third 

 the diameter of the orbit, which equals the distance between 

 the latter and the very small, round ear-opening ; forehead 

 scarcely concave. Head covered with small granules, which 

 are considerably larger on the snout ; rostral quadrangular, 

 not quite twice as broad as long, with a short cleft above ; 

 nostril pierced between the rostral, the first labial, and three 

 nasals ; twelve upper and ten lower labials j three or four 



* I have but recently seen Mr. Romyn Hitchcock's "Synopsis" of 

 Prof. Leidy's great work, and can confidently recommend it as a moat 

 useful compendium of information on the freshwater Rhizopods iu general. 



