Richard S. Bagnall — Fossil Insect in Amber. 483 



type is exceedingly erratic in occurrence ; in the very large zoarium 

 from which Fig. 9 is taken they are not as numerous as one per 

 100 zooecia, while Figs. 8 and 10 show how numerous they can be 

 in exceptional cases. 



2. Sub-vicario>is, of the hour-glass type, very narrow, with the 

 covered centre much drawn out and the open ends short and rounded ; 

 very rarely a bar across the lower end is preserved. Avicularia of 

 this type are always present in abundance. 



The species appears to be confined to the Triminghara Chalk. 



EXPLANATION OF PLATE XXXV. 

 YiQ (All figures x 12 cliams.) 



1. Menibranipora cuculligera . ZoneotM.cor-angtiinum. Wallers Ash, Hants. 



2. ,, ,, ,, ,, Gravesend. 



3. ,, vestigialis ,, ,, Micheldever, Hants. 



4. ,, ,, ,, ,, Gravesend. 



5. ,, prcscipua. Trimingham. 

 6. 



7. 



8. ,, sacerdotalis ,, 



9. 

 10. 



II. — Fossil Insect in Ambek. 



On Stenuhothrips succineus, gkn. et sp. nov., an inteeesting 

 Teritary Tuysanoptekon. 



By EiCHARD S. Bagnall, F.L.S., F.E.S. 



(PLATE XXXVI.) 



THE thrips described herein was submitted to me by Professor 

 Branca of the Geologiscli-Palaeontologisches Museum, Berlin, 

 and is one of a small collection of three examples in Baltic Amber. 

 The genus is curious on account of the abnormal tube-like development 

 of the tenth abdominal segment, which, however, is open ventrally 

 for its entire length. In the form of the antennae, so far as can be 

 ascertained from the single example and the structure of the wings, 

 Stenurothrips would seem to show affinity with the Neotropical genus 

 Heterothrips, and for the present I regard the genus as falling in the 

 Heterothripidse. 



In the generic description I have stated that there is a cross-vein 

 connecting the two longitudinal veins of the fore-wing near the basal 

 third. In this example I think I can discern this cross-vein, which 

 is shown somewhat markedly in the figure, but it is open to some 

 doubt. In another species of the same genus now before me, and 

 chiefly separated from the present species by the more minute spines 

 of the fore- wing, the wings are spread out, and this cross-vein is 

 distinctly discernible. 



Whilst I have been able, by various lighting arrangements, to 

 obtain a close detailed report of the upper surface, it has been 

 impossible to make out the mouth-parts, the legs, which are tucked 

 under the body, the basal part of tube ventrally, etc., on account of 

 a thick milky cloudiness, which, in a lesser degree, also somewhat 



