L ARRIVE. 165 



cealed, with a single spine at the apex of the intermediate 

 tibire ; the abdomen is ovoid-conical." 



The genus Astata is a large hairy form, with long antennte 

 and palpi and an elongated prothorax. Its spiny legs show its 

 near relationship to the SpJiegidce.' Astata unicolor Say repre- 

 sents the genus in this country. 



Tachytes is also of larger size than the following genus. 

 It is covered with long dense golden short hairs, with a trap- 

 ezoidal front. Tachytes aurulentus Fabr. is rare ; it frequents 

 the flowers of the Asclepias, as we have found pollen masses at- 

 tached to the spines of its legs. We figure 

 (89) a tarsus of a wasp belonging probably to 

 this genus, received from Mr. V. T. Chambers, 

 showing the pollen masses of Asclepias at- 

 tached to the spines. 



The genus Larrada "contains those species 

 which have the marginal cell truncated at the 

 apex and appendiculated, and three stibmarginal 

 cells, the first as long as the two following ; 

 .... the metathorax [propodeum] truncated 

 posteriorly, elongate, the sides being generally 

 parallel ; the mandibles are large and arcuate, 

 with a tooth on their exterior towards the base ; abdomen 

 ovate-conical, acuminate at the apex." Larrada argentata 

 Beauv. is covered with silvery pile. It is a slender form, with 

 short, nearly unarmed legs. 



A Brazilian species of Larrada, according to Mr. H. W. 

 Bates, builds a nest composed apparently of the scrapings of 

 the woolly texture of plants ; it is attached to a leaf, having a 

 close resemblance to a piece of German tinder, or a piece of 

 sponge. The cocoons were dark brown, and of a brittle consist- 

 ency. The reporter, Mr. F. Smith, adds : "I am not aware of 

 any similar habit of building an external nest having been pre- 

 viously recorded ; our British species of the closely allied 

 genus Tachytes, are burrowers in the ground, particularly in 

 sandy situations ; their anterior tarsi are strongly ciliated, the 

 claws bifid and admirably adapted for burrowing. On examin- 

 ing the insect which constructed the nest now exhibited, I find 

 the legs differently armed ; the anterior pair are not ciliated, 



