NOTES AND MEMORANDA. 267 



phases of the development of Crustacea can be distinguislied ; and 

 that, on the other baud, their development shows the closest resem- 

 blance to that of the Scorpions and other Arachnida. 2. That the 

 affinity between the Limuli and Trilobites cannot be doubted ; and 

 that the analogy between them is the greater in proportion as we 

 examine them at a loss advanced period of their develoi^ment. 3. That 

 the Trilobites, as well as the Eurypterid^e and Poecilopoda must be 

 separated from the class Crustacea, and must form, with the Arachnida, 

 a distinct division. 



NOTES AND MEMOKANDA. 



A Medical Man's Pocket-Case for Specimens, of an ingenious and 

 simple description, is that described by Dr. I. N. Durnforth in the 

 first number of the ' Lens.' It consists of a thick slab of plate glass, 

 in which six deep cells are excavated. The cover consists of another 

 plate of glass, of the same size, and the two are fastened together by 

 a strong rubber band. By means of this simple device specimens of 

 pus, of expectoration, of mucus, or of solid tissues, may be easily 

 transferred without being either dried or soiled ; and if a drachm 

 vial of carmine solution be also carried along, and a drop or two be 

 added when the specimen is first obtained, it will be stained ready for 

 the examination by the time the physician reaches home. Wrappings 

 of any kind of cloth or paper are totally unfit for the transportation 

 of specimens, as every microscopist very well knows. The compound 

 cell, which he has described, furnishes a cheap and simjjle, as well as 

 compact and portable, means of carrying as many specimens as any 

 physician would be likely to accumulate in a single day. 



A Modification of Dr, Matthews' Turn-table has been suggested by 

 the originator. Dr. Matthews said, at a late meeting of the Quekett 

 Club, that most of the members would, no doubt, recollect that he had 

 produced a self-centring turn-table, nearly two years ago (May 27th, 

 1870), and exhibited it at one of the meetings. It was then j^ro- 

 nounced to be excellent, and it remained excellent for new slides, but 

 in most cabinets there occurred a necessity for revarnishing old slides, 

 and cells on these were not always found to be central. In such 

 cases this turn-table would only correctly centre them, and thereby 

 show their eccentricity, and its accuracy thus became a defect, 

 although it was a defect consequent upon its perfection. He had, 

 however, now devised a remedy for this by dividing the top of the 

 table into two portions, so arranged that by sliding the upi)cr part 

 upon the surface of the lower, any required degree of eccentricity 

 could be attained. This was accomplished very easily and simply, 

 and he thought that the arrangement rendered the turn-table as 

 perfect as could be desired ; certainly he did not himself see what 

 more could be done to it. One of the improved turn-tables was then 

 VOL. VII. U 



