1881.] ON LACERTA AND ACANTHODACTYLUS. 739 



impregnated, but that a specimen got on the date above mentioned 

 was in preparation to receive the semen. 



I recommenced my labours tlie following year on August 12, 

 and completed them on September 29. These specimens I also 

 forwarded, through my father, to Professor Owen, who found two 

 examples impregnated, one killed on the 30th of August and the 

 other on the 14 th of September, a report of which cases he read before 

 the Royal Society in April 1880. Unfortunately, a specimen got on 

 September loth, which I delayed dissecting until next day, produced 

 a young one during the night, but in the morning was in too decora- 

 posed a state to preserve. 



It is therefore evident that in this part of Queensland the proper 

 time to get an impregnated specimen of the Echidna with the young 

 in the uterus is in September and October. I was under the impres- 

 sion, through my earlier observations, that the males do not go with 

 the females after the copulating season ; but this is not the case ; 

 I am sure, however, that after impregnation the females go away by 

 themselves, and do not mix with the males until after the young is 

 born. 



I am of opinion that neither the young males or females have 

 any sexual intercourse until their second year, as I have many young 

 males with their testes in a dormant state and young females with 

 the ovaries unexcited. Also, from observation, I am led to believe 

 that the females only breed every second year, as many of my older 

 specimens were not impregnated nor in any way prepared to receive 

 the semen. 



3. On tlie Lizards of the Genera Lacerta and Acanthodac- 

 tylus. By G. A. Botjlenger, 



[Eeceived May 31, 1881.] 

 (Plates LXIII., LXIV.) 



Thirty-five years have elapsed since Gray's * Catalogue of Lizards ' 

 was published ; and a great number of the species tlierein described 

 still remain objects of difficulty to herpetologists. This is due 

 chiefly to the shortness and ambiguity of Gray's diagnoses, which do 

 not allow of the identification of his species, nor give an exact idea 

 of their affinities. 



With regard to the family Lacertidse, no one has as yet attempted 

 to make out the species enumerated in the ' Catalogue of Lizards.' 

 Whilst engaged in naming some LacertcB and Acanthodactyli, I 

 recognized the necessity of going through all the species of these 

 two genera ; and I have the pleasure of laying before the Zoological 

 Society the result of this work. Beside the species contained in 

 Gray's Catalogue, I have also taken notice of those described since 

 by Dr. Giinther. This paper, therefore, is a critical account of all 

 the species of Lacerta and Acanthodactylus represented in the 

 British Museum. 



