238 BULLETIN 34, UNITED STATES NATIONAL MUSEUM. 



REPRODUCTION. 



The Salientia have, in temperate climates at least, an annual period of 

 reproduction, wliicli occurs in the spring. The male is without intro- 

 mittent organ, and fertilization is accomplished by the discharge of the 

 spermatic fluid of the male on the eggs as they leave the body of the 

 female. In order to accomplish this effectually the male attaches him- 

 self to the female by seizing her with his anterior limbs. In the 

 greater number of the Salientia the embrace is round the axill.T-, but iu 

 the Discoglossid?e, which approach nearest the salamanders in their 

 anatomy, the embrace is, as in those animals, round the loins. In the 

 salamanders it is, however, the hinder feet that seize the female, and 

 not the arms. Among other families the genera Cultripes, Pelobates, 

 and Pelodytes also seize the female around the waist. It is probable 

 that this will be found to be the case in some other genera not yet 

 observed.* 



The species of Arcifera exhibit peculiar structures during the breed- 

 ing season ; either an extension of the natatory membrane, or the 

 development of corneous plates or spurs, as aids to prehension. There 

 is much variety and etiiciency displayed in this point (except in Bufo- 

 nidfe), in especial contrast to the apparent absence of all but the weakest 

 modifications among the Eauida?. This is in compensation for the 

 structure of the sternum, whose lateral halves, being movable on each 

 other, offer a slighter basis of resistance for the flexor and extensor 

 muscles of the fore limbs. 



In the Discoglossidfe, Bombinator extends the natatory membrane 

 in the male, but does not develop horny plates. In Discoglossus two 

 file-like oval plates cover the superior surface of the short second digit 

 and the tubercle4ike first or thumb, which is here developed as in no 

 other anurous batrachian. Dermal rugosities on the upper and under 

 surfaces, including the gular region, are armed with corneous tips, as in 

 Telmatobius. No peculiarity has been noticed in Alytes. The Aste- 

 ro[)hrydida^, are unknown as to this point. 



In Pelodytes file-like plates are developed one on the second and one 

 on the third digit, one much larger on the forearm, one slightly smaller 

 on the inside of the humerus, and a small one on each side of the breast. 



Among ScaphiopidtTe the American species develop elongate laminse 

 on the superior inner face of the inner (second), third, and even fourth 

 digits. No peculiarities are recorded as appearing in the European 

 species. Many Hylidie — Agalychuis, Trachycephalus — develop a cor- 

 neous shield on the inner superior aspect of the inner metacarpal, which 

 is prolonged on the digit. 



While no appendages of the season have been observed iu some 

 Cystignathidfe, in several genera two acute spurs appear on the superior 



* Oil account of this diffei'ence MM. Thomas aud Delisle have i>roposed to divide 

 the Anura into two groups, naming them the Alamplexes and luguiuamplexes. See 

 Journal deZftologie, vi, 1877, p. 472. 



