Mr. J, Miers on the Bignoniacere. Ill 



9. Pentarthrum Monizianum and Bewickianum (Ann. Nat. 

 Hist. 3rd ser. v. 450, 451, 1860). — When describing these two 

 insects last year, I stated the exact points of their structure in 

 which they recede from Pentarthrum proper, as then represented 

 by a single species (the P. Huttoni), discovered by my nephew 

 eight years ago in the west of England; and I merely admitted 

 them into that genus on account of their 5-jointed funiculus, 

 and through a disinclination to multiply names more than was 

 absolutely necessary amongst these small members of the ligni- 

 vorous Rhynchophora. Since my diagnoses, however, were pub- 

 lished, the detection of another true Pentarthrum,, by Mr.Bewicke, 

 in the Island of Ascension, has so completely confirmed my 

 original formula of the group (vide Ann. Nat. Hist. 2nd ser. 

 xiv. 129, 1854), that, as recently stated in my paper (above 

 alluded to) on the Atlantic Cossonides, it can no longer be made 

 to embrace these two (nearly blind) Madeiran Curculios; and I 

 consequently proposed for them the generic title of Mesoxenus. 

 They must therefore be quoted as the Mesoxenus Monizianus 

 and Bewickianus. For the precise differential characters of the 

 genus, 1 must refer to my last year's paper in the ' Annals of 

 Natural History/ and to a recent memoir on the " Atlantic 

 Cossonides " which has just been published in the ' Trans, of the 

 Ent. Soc. of London/ 



XL — Observations on the Bignoniacece. 

 By John Miers, F.R.S., F.L.S. &c. 



[Continued from vol. vii. p. 396.] 



In the herbarium of the British Museum I find a plant, in 

 fruit, from the neighbourhood of Rio de Janeiro, the seeds of 

 which differ from those last described : the specimen has no 

 flower, so that it cannot be determined to be a species of Ade- 

 nocalymna*. The capsule is compressed, not cylindrical as in 

 A. scansile, and the valves are proportionally thinner. The 

 seeds are uniserial and much more compressed ; the central disk 

 is testudiniform, one of its sides, that of the hilum, being straight, 



* I take this opportunity of confirming what I formerly stated (vol. vii. 

 p. 266) concerning the little dependence to be placed on the calyx as a con- 

 stant and unerring test for generic discrimination. Perhaps no genus in the 

 family offers a more striking feature than Adenocalymna, in its peculiar 

 calyx, which gave origin to its name ; but I find in Gardner's collection a 

 plant, allied to Dolichandra, with an entire, tubular, coriaceous, pulverulent 

 calyx, marked with polished glands placed biserially below the margin, 

 just as in Adenocalymna ; and yet it is far removed from that genus on 

 account of the difference of its habit, of its corolla, in the structure of its 

 anthers, its ovary, its thick flat siliquose capsule, and its seeds. 



