of some species of Chrysomela, §'e. 181 



dilatato, breviter semi-ovato, illo tarsi }30stici paullo lon- 

 giori ; palporum maxillarium articulo ultimo late trun- 

 cato, quam penultimo latiori; abdominis segmento anali 

 trilobato, lobis obtusis, fere aiquilongis ; telo elongate, 

 curvato, apice linguiformi, apice ipso paullo deflexo ; 

 ducto quam telo breviori, dorso canaliculato, apice bifido. 



Foem. — Palporum maxillarium articulo ultimo ad pen- 

 ultimum a3quilato aut vix latiori; abdominis segmento 

 anali apice angulato-rotundato, integro. 



Long. 4 — 5 lin. 



Hab. — Eastern Siberia, Lake Baical; Mongolia. 



Thorax nearly twice as broad as long ; sides thickened, 

 straight and nearly parallel from their base to beyond the 

 middle, thence rounded and converging to the apex, the 

 hinder angles acute, the anterior ones moderately pro- 

 duced, obtuse; disk rather strongly and somewhat closely 

 punctured, a very narrow longitudinal line on the middle 

 disk (sometimes obsolete) free from punctures; the lon- 

 gitudinal space bounding the thickened lateral margin 

 deeply excavated from its base nearly to its middle, 

 slightly excavated in front, less broadly interrupted in 

 the middle than in speciosa ; its whole surface much more 

 coarsely and irregularly punctured than in its congeners. 

 Elytra regularly oval, not dilated behind the middle, 

 convex, aciculate-punctate ; interspaces irregularly but 

 less coarsely wrinkled than in speciosa and its allies ; 

 each elytron with three broad, shallow, ill-defined longi- 

 tudinal sulcations, Avhich extend nearly the whole length 

 of the disk ; in some specimens these grooves are much 

 less distinctly marked, in others (CV*. basilea, Gebl.) they 

 are entirely obsolete. 



When these sulcations are present, they alone will 

 separate the insect from its allies ; when absent, the 

 narrow elongate-ovate form of the body, and the regularly 

 ovate elytra, not dilated posteriorly in either sex, Avill at 

 once distinguish the species from all others of the same 

 sub-group. 



The apex of the anal segment of the abdomen in the $ 

 is similar in shape to that of speciosa ; in the ? it closely 

 resembles bifrons, but is rather shorter and less distinctly 

 angulatc. 



The two forms of the above insect stand in our cabinets 

 mider dillerelit names, given them in the same paper by 



