106 



THE AMERICAN MONTHLY 



[June, 



cally, some specimens of the foramin- 

 ifei-a collected by the Fish Commis- 

 sion steamer ' Albatross ' during the 

 last 1 8 months, and selected, pre- 

 pared, and mounted on board during 

 the cruise. 



The specimens before you are the 

 beginning of what is intended to be 

 a type series of this interesting group 

 of animals. It already includes rep- 

 resentatives of all the orders except 

 Gromidae, which are principally 

 fresh-water forms, and about half the 

 genera mentioned by Brady in his 

 Challenger Report, and numbers i 2^ 

 species. The collections were all 

 made on our Atlantic coast, and 

 with the exception of a very few — 

 not more than half-a-dozen species — 

 were taken off the coast between 

 Cape Hatteras and Martha's Vine- 

 yard . 



Great tjuantities of this material are 

 obtained by the Albatross, and its 

 separation and preservation have 

 been greatlv facilitated by the devices 

 of Mr. Benedict, the resident nat- 

 uralist of the ship. The material is 

 brought up from the bottom by 

 means of what is known in the ver- 

 nacular as the ' mud-bag,' a canvas 

 bag about 2^ feet long by i8 inches 

 wide, the mouth held open by an 

 iron frame. This bag is attached to 

 the free end of the net of the beam- 

 trawl, and it rarely fails to scoop its 

 full of mud as it is dragged over the 

 bottom. Being brought to the sur- 

 face the mud is dumped into the ta- 

 ble-sieve, the hose turned upon it, 

 breaking up the lumps and carrying 

 all but the coarsest particles through 

 the sieve, where it falls into a tub 

 below. This tub has several holes 

 at difterent heights at the side ; these 

 holes are stopped with spouts and 

 over the spouts are fastened strainers 

 made of fine linen 'scrim.' The 

 heavier foraminifera fall at once to 

 the bottom of the tub, the impalpa- 

 ble mud and the lighter foraminifera 

 flow out through the openings of the 

 tub, where the latter are stopped by 

 the strainers. The material thus ob- 



tained is a comparatively clean mix- 

 ture of sand and foraminifera, the 

 proportions of each depending upon 

 the nature of the bottom. Before 

 being ready for examination this ma- 

 terial requires a further thorough 

 washing by decantation. It must 

 then be v^^ashed with fresh water to 

 prevent the formation of crvstals of 

 salt, and thoroughly dried. 



The individual shells are picked 

 out under a dissecting microscope 

 by means of a fine camel's-hair pen- 

 cil, moistened between the lips. 



I may be excused for calling your 

 attention to the method of mounting, 

 since it is the only thing connected 

 with the subject for which I can 

 claim anv originality. It was soon 

 found that for the purpose of thor- 

 ough studv for identificiAion of speci- 

 mens the usual method of permanent 

 mounting was extremely unsatisfac- 

 tory. For the examination of objects 

 of this character under the microscope 

 nothing can equal what is known as 

 Beck's disks and holder. By means 

 of this accessorv an object may read- 

 ih' be rotated in the field of view of 

 the microscope so that all sides of it 

 maybe examined except that actually 

 adherent to the disk. These disks are 

 made of brass, with a short stem for 

 insertion in the arm of the holder. By 

 means of a fine chain concealed w.ithin 

 the arm and passing around the axle 

 of the milled head, rotation around a 

 perpendicular axis is obtained ; and 

 the whole arni being permitted to re- 

 volve in its support, rotation around 

 a horizontal axis is also secured. By 

 a combination of these movements the 

 object mav be placed in any desired 

 position without losing it from the 

 field of vie\v. The great advantages 

 attending the use of this appliance led 

 to the mounting of the whole series 

 upon disks, anv one of which may be 

 placed in the holder and thoroughly 

 examined. The specimen being se- 

 cured to the disk, the latter is inserted 

 into a wooden slide of the usual di- 

 mensions, and may be arranged in a 

 cabinet in the ordinary way. For the 



