218 Miscellaneous. 



broken out near the middle of the left side, and not far from the 

 sinus of the aperture. The opening was of a semilunar form, about 

 lj inch long, with an average breadth of half an inch. A new 

 deposit of testaceous substance, together with a broken fragment, 

 has closed the opening in the 1-ude manner common in the shells of 

 Mollusca. 



But the most extraordinary circumstance is this ; that a fragment, 

 which was broken out in the accident which befell the animal, now 

 constitutes two-thirds of the repaired portion, and that the originally 

 inner surface is now the outer surface, as is evident from its con- 

 cavity, style of undulation, and texture. It is also nearly at right 

 angles to its original position. These facts show that the piece was 

 totally detached from the shell by the accident. 



We apprehend that a case could scarcely occur, especially in a 

 shell moving in water, except in consequence of the functions now 

 ascribed to the vela of the Argonaut. These once-reputed sails, 

 performing the less poetic function of clasping and enveloping the 

 shell, prevented the loss of the large fragment. 



It is obvious also that the new deposit of testaceous matter was 

 secreted from the part of the animal within the shell, and not from 

 the vela, since the edges of the original shell around the fracture ap- 

 pear exclusively on the outside. 



Since none but the original inhabitant of the shell could repair it, 

 the case described is corroborative of the opinion, that the animal 

 usually seen in these shells is the original owner. — From Sillimans 

 Journal for July 1848. 



Notes on Chalcidites and other Insects. 

 By Francis Walker, F.L.S. 



A large woody gall is not uncommon on the twigs of the willow ; 

 it is inhabited by the grub of Cecidomyia Salicis, which is often a 

 victim to its enemies, and does not attain the fly state ; this is in 

 accordance with the law of nature which ordains a rapid diminution 

 of the individuals of most kinds before they attain their last form, 

 and thus their increase and the consumption of their food is lessened* 

 and their consequent starvation is prevented. Some of these galls 

 which I collected in the spring produced six or seven of the Ceci- 

 domyia, and the following numbers of parasites : — 



Pteromalus (Seladerma) Salicis, 67 males and 71 females = 138. 

 (I have also found it in Finmark.) 



Encyrtus Tennes, 10 males and 64 females = 74. 



Platygaster niger, 115, chiefly females. 



Tetrastichus jlavo-varius (Eulophus flavo-varius, Nees = Tetra- 

 stichus Armceus , List of Chalcidites in the British Museum, 74). This 

 fly has been reared from a larva in the buds of Ulex nanus by Mr. 

 Clear of Cork, who has also obtained Encyrtus serricornis from a 

 pupa of one of the Hepialidce ? ; " the original inhabitant was com- 

 pletely consumed, and nothing left but a transparent film." 



