armed ares in the Hymcnoptcruus genus (Julleks. 49 



elongate, and the sinuation of their apical margin hardly 

 so strong. Their discs are also as a rule much less deeply 

 infuscated. 



Two further points about the synonymy of hylseiformis 

 are puzzling. 



(1) Morawitz says that the species is probably identical 

 with nasutus, Smith. Yet as he describes it, it is evidently 

 as different as possible from the lattei', which is perhaps 

 the most unmistakable species of the whole genus. I 

 can only suppose that Morawitz did not know the real 

 nasutus when he revised Eversmann's collections. 



(2) V. Dalla Torre gives " hyhviformis, Perez," as -^xo- 

 hsih\y = aca^ithojrygus, Dours. But certainly the hylxi- 

 formis $ $ 1 have received from Prof. Perez and Herr 

 Kohl by no means answer to Dours's description of 

 acantlwpygus. The latter should have a strong spine at 

 the apex of the abdomen. Such a spine in a Colletes-sp. 

 I never saw. Is it possible that Dours has been deceived 

 by some $ in which a stipes of the armature accidentally 

 protruded from the abdomen ? (His " types " seem to have 

 disappeared.) 



9. Eatoni, n. sp. PI. VI, 9, 9a, 9&. 



Simillimus caspico, sed abdomine nuilto subtilius et sequalius 

 densissime puuctulato. Pilositas mesonoti pallida, non nihil flaves- 

 cens. Fasci;e abdomiualis deusae, latissimie, nive.'e, iu ? vix minus 

 qiiain in hylseiformi squameiTe. ^ stipitibus ut in caspico i'ormatis, 

 scilicet apicibus baud productis sed oblique truncatis. Genae breves. 

 (Corp. long. (J circa 10 mill., $ circa 12 mill.) 



This beautiful insect is closely allied to caspicus by the 

 structure of its armature and seventh ventral plates, but 

 easily distinguished from it in both sexes by the extremely 

 fine, close and even puncturation of the abdomen, and in 

 the $ by the shorter and paler pilosity, which on the 

 abdomen, though not on the thorax, is almost as squami- 

 form as in hyLvi/ormis. It appears to me to stand to 

 casjncus much in the same relation as pcrezi to haltcatus. 

 The first abdominal segment is densely clothed at the base 

 with white pilosity ; there is also a dense basal band on the 

 second segment, which, as well as all the apical fasciae, is 

 entire, very broad, and of the purest silvery-white ; the 

 pubescence on the discs of the segments is very short and 

 dark, making the fasciae show up very sharply in contrast 



TKANS. ENT. SOC. LOND. 1904. — PART I. (APRIL) 4 



