Sowid-proditcHon in the Lamellicorn Beetles. 741 



There are two species of this anomalous genus in the 

 British Museum, of which the typical one is diagnosed 

 as follows : — 



Idiostoma rufum, sp. n. 



Plate XXXVI, fig. 1. 



Rufum, obesuni, capite parvo, rugoso, autice bidentato, fronte 

 tuberculo, fcemirife obsolete, maris modice recurvato-producto, 

 armato ; prothorace grosse sat crebre piinctato, medio longitudi- 

 naliter canaliculato, foeminaj leviter, maris, profunde, liujus ^ ex- 

 cavationis lateribus utrumqiie acuminatis, protboracis lateribus 

 valde curvatis, angulis anticis obtusis, posticis obsoletis ; scutello 

 acuminato, Itevi ; elytris valde coiivexis, politis, sulcatis, interstitiis 

 minute baud dense punctulatis, intervallo suturali antice et postice 

 contracto. 



Long. 12-16 mm. 



Hab. W. Patagonia, Valle del Lago Blanco. 



The Museum possesses a number of specimens, most of 

 them males, of this interesting insect, brought from the 

 eastern slopes of the Andean chain. All are of a reddish- 

 chestnut colour, thickly clothed beneath with tawny hair. 

 The thorax is relatively rather small and is rather narrower 

 at its broadest part than the elytra at the shoulders. 



The second species is described from a single male 

 specimen acquired many years ago, and, although the 

 distinctive features are sufficiently marked, it is not ad- 

 visable, until additional specimens are available, to describe 

 it in very great detail lest merely individual features 

 should be taken as characteristic. Our specimen bears 

 the unpublished name of Medon Patagoniie, Reiche, in the 

 writing of the French entomologist Jekel, from whom it 

 was obtained. It may be called 



Idiostoma Medon, sp. n. 



I. rufi simile sed multo minor : rufo-castaneum, elytris lateraliter 

 pallidioribus : clypeo late truncato, baud dentato : protborace latins, 

 minus profunde, excavato, excavationis lateribus baud acuminatis : 

 elytris magis seqiialiter sulcatis, intervallo suturale vix con- 

 tracto ; calcaribus tibialibus omnibus acutis, maris pedum anticorum 

 hand spatulatis. 



Long. 9 mm. 



Eab. Patagonia. 



In addition to the much smaller size, differently shaped 

 head and thorax and more parallel elytral striae, our 



TRANS. ENT. SOC. LOND. 1904.— PART IV. (DEC.) 48 



