268 NOVITATKS ZOOLOGICAE XXII. 1315. 



wings, are more strongly marked in saua than iu algiriae, the diffuse brownish 

 discal band of the bindwing above also being more pronounced in sana than in 

 algiriae. This distinction is near!)- constant, very few specimens of both species 

 being intermediate. 



The true differences between sana and algiriae do not appear to have ever 

 been described. They are very striking, and are found in the neuration and legs 

 of both sexes and iu the antennae of the males. 



In Hampson's Key to the Genera of Catocalinac the relative length of the 

 cell of the bindwing is employed as one of the distinguishing characters. If the 

 Key were strictly adhered to, Cerocala algiriae and C. sana would be located in 

 separate groups of genera ; for the difference in the lengths of the cells of the 

 bindwing is very marked in the two species. The proportion between the length 

 of the cell measured from the base of the wing to the lower cell-angle and the 

 length of the lower radial vein (= vein 4) is 4 : 5 in algiriae, and 4 : 7 in sana. 

 These proportions place algiriae into the neighbourhood of Euclidimera mi and 



Figs. 5 and Q.—Ccrncnla algiriae, 

 „ 7 „ 8. — ., Sana. 



Caenurgia fortnlitium, while sana has the shorter cell of the other (all ?) species 

 of Cerocala. However, it would be a very unnatural classification, if algiriae 

 were placed far apart from sana. 



The second distinction refers to the claw-segment of the tarsi. In .^ana the 

 pulvillus or flap situated iu between the claws has a very distinct black apical lobe 

 (text-figs. 7 and 8, P), which can readily be seen with a fairly strong lens. This 

 pulvillus is absent in algiriae (text-figs. 5 and 6). The majority of the other species 

 of Cerocala, if not all, agree with sana in the possession of a distinct pulvillus. 

 This character, in conjunction with the previous, renders it easy to separate both 

 sexes of Sana from algiriae. 



While these are all the distinctions I have found between the females of the 

 two species, the males exhibit farther differences. If the antennae are compared 

 side by side, the filamentous apical portion appears much longer in .<tana than in 

 algiriae, which is due to a number of distal segments being simple or dentate 

 in sana, while all the segments are pectinated iu algiriae, with the exception of 

 the last one or two. The difference in the shape of the segments and the length 



