12 Mr. MacLeay on some new forms of Arachnida. 



thing is certainly known with respect to the manners of these 

 curious spiders, but I suppose, from analogy, that they may 

 eventually be found to feed on ants. Itjias been long known 

 that the Volucellce in their larva state live in the nests of the 

 Bombi they so much resemble ; and I have discovered that 

 the larvae of those tropical Bombylii which have such a bee- 

 like form live on the larvae of the bees they so strikingly repre- 

 sent. Perhaps, in like manner, the object of nature in giving 

 such a striking form to this spider is to deceive the ants on 

 which they prey. 



Attus of Walckenaer is a very good subgenus, if the name 

 be confined to such ant-like insects as Aranea formicaria of 

 DeGeer, and Attus formicoides of Walckenaer. Latreille's 

 name, Salticus, ought therefore to be confined to those salti- 

 grade spiders of which the Aranea scenica of Linnaeus may be 

 considered the type. This, however, is an use of the two ge- 

 neric names the very reverse of that which is proposed by 

 Sundevall in his description of the spiders of Sweden. 



Plate I. Fig. 4. Myrmarachne melanocephala, magnified, x, system of 

 eyes ; /3, antenna ; y, abdomen viewed laterally. 



Genus OTIOTHOPS. 



Antennce short, having the first joint transversely vertical, 

 subcuneiform, and the second joint or fang minute and 

 horizontal. 



Eyes eight ; the four frontal ones disposed in a transverse 

 line, of which the two on the outside are the least and 

 suboval ; behind these last there are two other eyes placed 

 small and round ; and the remaining two are in the mid- 

 dle between them only placed further behind ; these two 

 are so confluent that to the naked eye the spider seems 

 to have only seven ocelli. (In my specimen the right 

 ocellus is evanescent, and the left is very large and of a 

 silvery lustre.) 



Maxillce large, subtriangular, truncated at the apex, and 

 having the palpi inserted at their very base. 



Maxillary palpi with the penultimate joint short, and the last 

 one long, triangular and hirsute. 



Labial palpi vertical, not pediform, six-jointed ; first joint 

 curved, thick ; second semilunar, much incrassated ; third 



