Bacillaria (bass-ill-air-ee-a) paxillifer, a colonial planktonic diatom, in which many cells join by their raphes, and can slide against each other. The resulting arrays are capable of extending and retracting, not exactly like a pantograph, but not too different either. This species from the plankton, some say it is the same as the benthic
B. paradoxa. This image shows a number of colonies. Bright field.
data on this strain.