14 The Scottish Natiiralisi. 



* 



Acer pseudoplatanus L. — From the upper surface of the leaf 

 project 'nailgalls/ cylindrical or dilating upwards, about 

 Vs ^ Yie iiich, externally bright red and naked. On the 

 lower surface of the leaf are found small pits, in the 

 centre of each of which a gall opens by a small hole 

 nearly blocked up with projecting transparent simple 

 hairs. On section the interior is found to be smooth 

 above, or covered with minute warty tubercles. Galls 

 examined in July showed multitudes of the makers, viz. 

 a species of Phytoptus^ — Ceratoneon indgare Bremi, = 

 Volviclifex aceris Amerling. The galls are common at 

 Banchory on Deeside, at Perth, and at Glasgow. Usually 

 multitudes occur on each leaf 



Trifolium repens L. — {Sc. Nat. I. 195) The galls already 

 described as found on this plant are the work of 

 Cecidomyia trifolii F. Low. 



Prunus communis Hubs. var. spinosa L. — To Mr. Binnie 

 I am indebted for galls on the leaves gathered near 

 Glasgow, in September. They consist of a swelling 

 which projects like a bladder from the lower surface of 

 the leaf, and opens by a cleft along the midrib on 

 the upper surface. They are about ^ to ^ inch long, 

 and yk-y^i inch broad and deep. The walls are thin ^ 

 and the central cavity large. The outer surface is 

 green like the rest of the leaf When the gall is large 

 the leaf is sometimes reduced to a fringe along each 

 side of the midrib. Mr. Binnie informed me that all 

 he found were empty save one or two, but that 

 these contained larvaj of a Cecidomyia. 



PoTENTiLLA TORMENTiLLA L. — (Sc. Nat. II. 9 7. J The gall is 

 made by Aitlax ( XenopJianes ) potentillce Vill. Dr. Vice 

 found a gall of this species near Aberdeen. 



Crat^gus oxyacantha L. — (a) (Sc. Nat. I. 79). Galls 

 of Cecidomyia crataegi Winn. (U) In many places 

 throughout the country (Aberdeen, Perth, Glasgow, &c). 

 The margins of the leaves along one or more of the lobes 

 are revolute and thickened, forming tubes lined with 

 hairs, among which live the occuj^ants, viz., mites of the 

 genus Phytoptiis. The gall has been named Erincum 

 oxyacanthce by Persoon, and described as a fungus. I 

 is very noticeable, being pale greenish-yellow in colour 

 and usually occurring in large numbers. 



