258 Mr. Shuckard's Monograph of the Dorylidae, 



for it is clear, that, although Thelidomus opens the path to the 

 Helicida, there must be several other forms between the two, 

 either extinct or undiscovered," p. 228. — The bodies which 

 he here describes, and the " singular discovery" which he 

 represents as throwing an " entirely new light on this interest- 

 ing question", are "actually composed of little stones and 

 grains of sand only, agglutinated together," p. 227 and 353, 

 and are the cases of a caddis worm which is very common in 

 Brazil and the United States. It differs from the cases of 

 the European kinds in being spiral ; but it agrees with them 

 in being pervious at each end, though the hole at the smaller 

 end appears to have escaped Mr. Swainson's observation. 

 The North American cases have been described by Mr. Lea, 

 under the name of Valvata arenifera. It might have been 

 supposed that the ridicule which Mr. Lea has incurred for this 

 error, would have prevented any other naturalist from falling 

 into the same mistake. Indeed it is difficult to understand 

 how any one who considers the formation and structure 

 of shells, should not have reflected on the peculiarity of the 

 formation of these bodies before he described them, and pro- 

 ceeded to build up such important reasonings upon their 

 supposed place in his system. — John Edw. Gray. 



XXX. — Monograph of the Dorylidae, a Family of the Hyme- 

 noptera Heterogyna. By W. E. Suuckard, Esq. 



[Continued from p. 201.] 



Sp. 6. Labidus Hopei. Shuck. Length 6 lines. 



Expansion of the wings 12 lines. 



Rufo-testaceus, pubescens : capite {mandibuUs antennisqtie exceptis) atra; 

 thorace fusco, scutello in medio sulcata, et pedunculo abdominis transversa 

 quadrato, supra subconvexo. 

 Reddish testaceous, pubescent, the hair longest upon the legs, and beneath 

 the first ventral and the whole of the terminal segments of the abdo- 

 men. The head having the vertex and face deep black and shining, 

 the remainder castaneous, the carinae of the face terminating gradually 

 in front of the anterior ocellus j ocelli placed in a curve on the vertex ; 

 antennae slender, the scape about one-fifth the length of the organ ; 

 mandibles moderately long and very slender, having but a small open 

 space between them and the clypeus. 



