1877.! 10 



existing, but there seldom remains niucli difllcultv as to fixing tlio exact position of 

 these fossils, and evidence, either direct or collateral, is abundant to prove that the 

 insects entangled in the resin to which, in its fossil condition, vre apply the term 

 " Amber," were extremely similar to those of the present time. An important no- 

 tice by Menge (in the Schriften der Naturforschenden Gresellschaft in Danzig, neue 

 Folge, Baud i, 1866) has not been under consideration by any of the recent writers 

 on Stylopidce. Menge recorded the finding of a species, to which he gave the name 

 Triana tertiaria, and wood-cuts illustrated his notes. In many respects it is closely 

 aUied to the genus Stylops, but differs in the antennoe, and, from all existing genera, 

 in its 5-jointed tarsi. This discovery was of more than ordinary interest, because 

 the family, as it now exists, is of such small extent, and (although we have recently 

 heard of some extraordinary captures) of habits such as to make it a noteworthy 

 event for the males to be taken at large. Was the group nioi-o extensive and 

 common in former times ? or, is the finding of this solitary example to bo placed in 

 the category of lucky chances ? It is scarcely necessary to say that the collateral 

 interest attached to this almost overlooked discovery relates to the Hymenopterous 

 Fauna, and the corresponding condition of the Flora, of the Amber age. There 

 appears to be no doubt that the resin was that of a Conifer, and that the aspect 

 of the then-existing district was somewhat of the barren nature of our fir-forests. 

 So far as has been recorded, the Amber-insects do not give any evidence of abundance 

 of honey-producing flowering-plants. 



Notes on "Die Hemipteren-Gattung PUnthisus (Westio.J Fieh.," by Dr. 

 G. V. Rorvdth. — Under the foregoing title, in the " Verhandlungen der k. k. zool.- 

 botan. Gresells. Wien," xxvi, pp. 721—30 (1876), Dr. Horvath gives an excellent 

 memoir on the species of the genus Plinthisus, which is made to include, as sub- 

 genera, Plinthisiis, Fieb., Plinthisomus, Fieb., and Isioscyius, Horv. Thirteen 

 species are enumerated ; the synonymy is copious, several species previously 

 described as distinct being referred to others still older, in some cases by the identi- 

 fication of the macropterous and micx'opterous forms of a species. Thus our British 

 P. bidentulus is placed as the macropterous form of P. hrevipennis ; and I fully 

 believe this is correct. It is, however, only just to Herrich-Schaffer, who first 

 described P. bideidnlus, to cite his remark (Wanz. vi, 31, 1842) : "Fast mochte ich 

 glauben, dass gcgenwiirtige Art der vollstiindig entwickelte P. brevipennis ist, welcher 

 in Grosse, Farbe und Umriss des Thorax ziemlich abJindert." One species, 

 P. minutlssimus, Fieb., said, on the authority of Dr. Puton, to live exclusively in 

 society with ants, has hitherto been found only in the south of France and Upper 

 Italy, and always with rudimentary elytra and wings (Flugorgane) : but Dr. Puton 

 obtained in Algiers a Plinthisus with fully developed elytra, which Dr. Ilorvath, 

 after close examination, holds to be the macropterous form of this species. 



Dr. Ilorvath makes the following remarks on the genus : " The genus Plinthisus 

 forms a small, well-characterized group of the Dygceidce, sub-family Myodochidm. 

 The most conspicuous cliaracter consists in the rudimentary development of the 

 elytra and wings (Flugorgane). All the species have the elytra more or less 

 shortened; the clavus and corium are anastomosed, and the membrane is either 

 entirely wanting or at the most is reduced to a small, nan-ow marginal rudiment. 

 Ill the former case the elytra are so much abbreviated that Ihcy leave at least the 

 last three dorsal segments of the abdomen uncovered." 



