C)8 PHILOSOPHICAL TRANSACTIONS. [aNNO I764. 



thin as paper, but the alveolus is destroyed, except the apex or point. At 

 Thame, in digging for stone, several small ones were found in a stratum of blue 

 clay of a more cylindrical form (fig. 17); some of which have the pearly sub- 

 stance still remaining; an incontestable proof of their being marine productions. 



How much of the cavity is occupied by the alveolus cannot be truly ascer- 

 tained, until a |)erfect one can be found, which it will be hard to do in the fossil 

 state, but if we may judge from the nautilus, the walls are carried to a distance 

 from the last-formed valve, much greater than that at which the valves are placed 

 from each other: as in fig. 13, from a to b, which gives the animal all the con- 

 venience of forming a new valve or diaphragm, c. This circumstance has been 

 very ingeniously cleared up by a learned physician in the Gent. Magazine for Jan. 

 1752, p. 8. 



f^I. On a Singular Species of IVasp and Locust. By Samuel Fellon, Esq., 



F. R. S. p. 53. 



These species of wasp and locust, Mr. F. found in the Island of Jamaica, and 

 which he thinks have never been described. 



I. Crinita.* — Vespa setis colli thoracis abdominisque radiantibus corpore lon- 

 gioribus, fig. 8, pi. 1. 



It is as large as a common wasp, but rather narrower. The head is brown- 

 ish, the vertex black, in a triangular form. The antennae are shorter than the 

 thorax, a little thicker towards the end, of a yellow brownish colour ; but black 

 in the middle. The thorax is light brownish on the back, but on the sides and 

 underneath black: before the insertion of the wings, there are 2 yellow lines 

 running transversely downwards; just over the insertion of the wings two hairs 

 go out on each side of equal length, and very near twice as long as the whole 

 body ; from the upper part of the neck likewise go out two hairs as long as the 

 body. 



The abdomen is divided into 6 segments, of which the first is very narrow at 

 its basis, quite black, only the hind margins yellow; from this segment there 

 only grow out two hairs twice as long as the abdomen, at the base, but no 

 where else; the other 5 segments are between brown and yellow coloured, their 

 hind margins a little paler, and the second has a black girth near the fore mar- 

 gin ; hairs go out near the fore segment as rays ; in the 2d only 3, and they are 

 shorter than the abdomen, especially the side ones; in the 3d, 4th, and 5th 

 segments, there are 4 or 5 long hairs longer than the body, and several shorter 

 ones, especially underneath where there are no longer ones ; the 6th segment is 



• The singular appearance of this insect, which seems to be a species of sphex, is supposed to be 

 owing to a particular kind of filiform fungus springing from different parts of the animal : it is how- 

 ever highly remarkable that they should proceed with such regularity from the opposite sides of the 

 insect. 



