NATURAL SCIENCES OP PHILADELPHIA. 219 



variations occur in which the thorax is partly testaceous, and the elytra black, 

 with the margin and suture pale. 



20. G. m or os a Zee, Rep. Pacific R. R. Expl., 70. 



One specimen found on salt marsh at San Francisco, Cal. Resembles a black 

 individual of G. maritima, but the thorax is less narrowed in front, less 

 rounded on tbe sides, and the hind angles are not flattened ; the elytra are 

 more coarsely punctured, and the pubescence is longer and nearly white. 



TRIRHABDA Lee. 



Body elongate, not very convex, finely punctured and pubescent. Front 

 flat, with the usual impressions as in Galeruca ; not at all carinate between 

 the antennae ; maxillary palpi not very stout, with the last joint conical, acute, 

 as long as the preceding, and not smaller than it at the base ; antennae with 

 the third joint intermediate in size between the second and fourth. Prothorax 

 with a large, transverse, broad impression, which is disposed to divide into 

 three, being deeper at the middle and at the sides. Elytra distinctly margined 

 at the sides, with the epipleurae very narrow, and becoming indistinct about 

 the middle. Anterior coxae conical, prominent, contiguous ; tibiae not sulcate 

 externally ; ungues cleft at the tip, with the inner part a little shorter than 

 the outer. The last ventral segment in the males is slightly emargiuate. 



These species are of large size : the head and thorax are pale, the former 

 with an occipital, the latter with three discoidal black spots ; the elytra are 

 pale, with a broad sutural and discoidal black (or rarely green) stripes. In 

 some species these vittae coalesce, causing the margin only to remain pale. 



The differences in the proportion of the joints of the antennae and in the 

 epipleurae prevent these species from being retained in Galeruca. The 

 genus does not appear to be represented in Europe. 



The species may be distinguished as follows : 



Thorax smooth, polished, feebly impressed 1. nitidicollis. 



Thorax more or less punctured ; 

 Lateral and apical margins of elytra yellow ; 



Elytra extremely finely punctured ; 



Vittae black, generally uniting near the tip 2. canadensis. 



Vittaa green or bronzed, entirely confluent 3. luteocincta. 



Elytra moderately finely punctured ; 



Vittaa blue, entirely confluent 4. f 1 a vo 1 i mb a ta. 



Vittae blue, gradually approaching behind ; 



Larger, elytra more finely punctured 5. attenuata. 



Smaller, elytra less finely punctured 6. convergens. 



Vittae black, gradually approaching behind 7. tomentosa. 



Vittae black, not united at tip 8. virgata. 



Yellow margin of elytra not extending to the tip 9. brevicollis. 



1. T. nitidicollis, luteo-teatacea, occipue subtiliter punctato, nigro- 

 maculato, thorace latitudine vix duplo breviore, convexo laevi polito, angulis 

 haud prominulis, disco utrinque oblique impresso, guttis tribus nigris signato, 

 elytris subtiliter dense punctulatis et pubescentibus, vitta suturali alteraque 

 submarginali angustis cyaceo-nigris rnox ante apicem conjunctis ; antennis 

 fuscis. Long. -42. 



One specimen collected in New Mexico by Mr. Fendler. Easily distinguished 

 by the characters above given. The elytra are very little wider than the thorax, 

 and the sutural angle is slightly prominent, while in all the following speciea 

 it is rounded. 



2. T. canadensis. Galeruca canadensis Kirby, Fauna Bor. Am., i v. 2 1 9. 

 A common species, extending from Lake Superior and the Mississippi Valley 



to the Pacific. The black vitta? are regular, and generally are united near the 



1865.} 



