Zoological Society. 139 



Besides the two specimens, one from Bahia Blanca and the other 

 rather further south (San Bias), Mr. Darwin's collection contains a 

 specimen from Tierra del Fuego which is smaller (length 6j lin., 

 width 3 J lines) and proportionately narrower ; but these differences 

 are combined with a greater length of tarsus, and are precisely such 

 differences as exist between the sexes of other species ; in fact, it is 

 no doubt the male of the insect from which the above description is 

 taken. 



Nyctelia Westwoodii. Nyct. breviter ovata, nitida, atra; capite 

 subpunctato ; thorace transverso, postice paulb latiore quam antice, 

 levifer convexo, Icevi, margine laterali imperspicue crenulato ; ely- 

 tris ovatis, profunde striatis, interstitiis convexis, striis utrinque 

 ad suturam duabus longitudinalibus, striis reliquis obliquis. 



Long. corp. 1\ lin. ; lat. 4| lin. . 



Hab. Port Desire. 



Head with a few punctures in front. Thorax convex, about twice 

 as broad as long, with the middle and hinder parts about equal in 

 width, and the fore-part contracted ; the anterior part emarginated, 

 the emarginated portion in the form of a segment of a circle ; the 

 hinder margin but slightly waved ; a distinct groove runs close to 

 the anterior and lateral margins, which latter are crenulated. Elytra 

 short and rounded ; the length and width equal, if the produced apical 

 portion be omitted in the measurement; the apex is moderately 

 produced : the whole surface of the elytra is covered with deep striae, 

 leaving convex interspaces which are scarcely broader than the 

 grooves ; on each side of, and parallel with the suture, are two of 

 these striae ; the remaining grooves are oblique, and for the most 

 part converge towards the apical portion of the elytra : on the sides 

 of the elytra, and more especially towards the apex, the grooves have 

 a tendency to a transverse disposition. The mentum is very coarsely 

 punctured, and there are some distinct punctures on the sides of the 

 head beneath. The prothorax presents a few large scattered punc- 

 tures beneath, some short irregular (but for the most part transverse) 

 rugae at the lateral margin, and some longitudinal rugae near the base 

 of the legs ; between the legs the prosternum has some confluent 

 punctures ; the mesosternum and metasternum have irregular rugae, 

 and the three first abdominal segments have minute longitudinal 

 furrows ; the penultimate segment is smooth, and the apical one is 

 finely punctured, but the punctures are by no means numerous. 

 The legs and antennae are rather shorter than usual in the genus. 



Nyctelia Stephensii. Nyct. atra, nitida, Icevis ; thorace subqua- 

 drato ; elytris rotundato-ovatis, convexis, carind laterali promi- 

 nenti et crenulatd ; elytrorum apicibus productis latis et subcorn- 

 planatis. 

 Long. corp. 7 lin. ; lat. 4^ lin. 

 Hab. St. Cruz. 



Head with scattered punctures in front. Thorax transverse, the 

 width being rather less than double the length ; the upper surface is 

 but little convex; the anterior and posterior margins are nearly 



