37 



DESCRIPTIONS OF FIVE TADPOLES FROM SIAM. 



By Malcolm Smith, m.k.c.s., L.u.c.r. 

 With two plates. 



The following tadpoles have not been j'et described. 



That Cidlala indchra, the common "bull-frog" of Bangkok 

 and Singapore, should have remained so long unknown, is rather 

 surprising, considering how plentiful and easil}^ obtained it is. 



MicroJu/la ornata is iriteresting, on account cf the formation 

 of its mouth, which is modified in a peculiar waj' for obtaining food 

 from the sui'face of the water. 



Rana nifjrovittata and Bxofo parviu were obtained this j'ear in 

 the mountain streams of Khao Sebab, Chantabun. 



My thanks are due to Mr. C. L. Groundwater, for his very 

 careful drawings illustrating this article. 



Microhyla achatioa. 



Uead and body ; length, 1| times to twice its breadth. No-strils, 

 rather far apart, midway between the eyes and the upper lip. Eyes, 

 perfectly lateral, four times as far apart as the nostrils. Spiraculum, 

 median, the transparent sheath opening below the centre of the coil of 

 gut. Anal tube, median, long, curved, openiug at the lower edge 

 of the caudal membrane. Tail, twice as long as tiie head and bodj', 

 about four times as long as deep, terminating in a fine point ; crests 

 moderate, upper convex, at its greatest heiglit nearly as deep as the 

 lower, not extending on to the back ; lower crest nearly straight. Toes, 

 almost fully webbed. 



Mouth. I have left this until tiie last, as it presents unusual 

 features, and is quite different from that of the other three species of 

 Microhyla ( M. ornata, 2ndchr a, a.\v\ ruhra) at present known. As one 

 would expect in this typo of Hatrachian, it has neither beak nor teotli. 

 It consists of a hoise-shoe shaped upper lip and a cjntractilo lower one, 

 the lattei being furnishe i, in addif ion, witii a largo cutaneous expansion 

 or flap, which can bo erected or di^prossed at will. When the tadpole 



VOL. II, JUNK rJlli. 



