Species o/" Teredo. 31 



the source from which he copied it (fig. 17, c) ; the delineated 

 specimen * differs a little from the earlier representations of 

 it, being shorter than in Spengler's drawing (Skriv. Nat. 

 Selsk. vol. ii. pt. 1, pi. ii. fig. D). The statement that the 

 British Museum had furnished the specimens is an error. 



T. denticulata. — The reference should have been to Gray- 

 in Ann. & Mag. Nat. Hist. 1851, p. 386, where this name is 

 given, without appended description, to the undescribed and 

 supposed erroneous navalis of Moller. Naturalists might 

 have been congratulated that this undeterminable shell was at 

 length defined, onlj unfortunately the jagged tooth-like pro- 

 jection on the side of one of the pallets of the museum speci- 

 men (received from Moller, I fancy) seems the result of an 

 injury or malformation. Both sides of the pallet are repre- 

 sented as symmetrically jagged, but this was imaginative. 

 Mr. Edgar Smith remarks that the valves are inaccurately 

 drawn. 



In making these comments upon the monograph of a pecu- 

 liarly difficult genus, I wish expressly to declare that my 

 criticism is solely designed to prevent tlie perpetuation, or 

 origination, of errors which would spring from a misplaced 

 confidence in the existence of specimens in the national col- 

 lection. 



It is the only illustrated monograph of the genus, the 

 materials for which are too scattered and too rare to be 

 readily accumulated and compared. An abundance of speci- 

 mens and a fine library are absolutely indispensable to a 

 conscientious naturalist, and even to obtain access to the 

 latter is almost impossible for a scientific conchologist who 

 permanently lives in England. Kich shell-collectors buy 

 costly specimens, yet for names sponge upon the brains of 

 those whose books they refuse to purchase. 



* "Mus. Brit, and Sow." "No tube, valves, or pallet like these 

 drawings are in the museum." — Edgar Smith. 



