508 EECORD OF SCIENCE FOR 1886. 



have been added since that time. The largest proportion of them have 

 been described since 18S2. Forty-five of the new species are represented 

 by the types In the British Museum. (Proc. Zool. Soc. London, 1886, 

 pp. 411-416, pi. 39.) 



Varieties of ovipositon among the tailless amphibians. — Great variety 

 of oviposition is manifested by the tailless amphibiaus, and a very use- 

 ful resume of the information that has been collected up to the present 

 time has been published by Dr. G. A. Boulenger, in connection with 

 some observations by Dr. H. von Ihering '' on the oviposition in Phyl- 

 lomedusa." Most of the anurans lay their eggs in the water, but the 

 exceptions are numerous and some of them very siugular. Dr. Boulenger 

 groups the eggs i)rimarily into those in which the ovum is very small, 

 in contradistinction from others in which the yelk-sack is very large. 



In some " the ovum is small, and the larva leaves it in a compara- 

 tively early embryonic condition." Such are the ova of the great ma- 

 jority of the anurans. (1) Further, in most cases, they are laid di- 

 rectly in the water ; all of the European types except of the genus Alytes 

 display this mode of oviposition. (2) But by a few species "the ova 

 are dewosited out of the water." {a) Certain South- American species 

 deposit i^hem " in holes on the banks of pools, which become filled with 

 water afttr heavy rain," whereby the larvae are liberated. The species 

 so distinguished, as far as known, are Leptodactylus oceUatus, Leptodac- 

 tylus 7nystacim(s, and Paliidicola gracilis, (b) A couple of other species 

 likewise deposit their eggs out of the water, but instead of in holes, on 

 the leaves of trees hanging over the water, so that the larvse may drop 

 down into the water after leaving the egg. One of the species thus 

 distinguished is the Chiromantis rufescens^ of West Africa, and another 

 the Phyllomedusa Iheringii, of southern Brazil. 



In other anurans " the yelk-sack is very large and the young under- 

 goes the whole or part of the metamorphosis within the Ggg', at any 

 rate, the larva does not assume an independent existence until after the 

 loss of the external gills." 



In some of these " the ova are deposited in damp situations, or on 

 leaves, and the embryo leaves the egg in the perfect air-breathing 

 form." Such are a true frog, Rana ojyisthodon, of South America, and 

 a tree-frog, Hylodes martinicensis, of the island of Martinique. 



In other cases " the ova are carried by the parent." 



The parent in some instances is the male, {a) By the male of one 

 species the eggs are carried in a chain " around the legs," while " the 

 young leaves the egg in the tadpole state." Such a phase is manifested 

 by the Alytes obstetricans of Europe. (6) In another instance the male 

 takes care of the egg, but in another and very remarkable manner, for 

 the eggs are carried about in a gular sack, which is simply a modification 

 of the vocal, and " the young is expelled in the perfect state," such as 

 the Rhinodenna. 



