a. and sb. Zool. [ad. mod.L. tetrabranchiāt-um: see prec. and -ATE2 2.] a. adj. Belonging to the Tetrabranchiata, an order of cephalopods (mostly extinct) having four branchiæ or gills. b. sb. A cephalopod belonging to this order; a tetrabranch.

1

1835–6.  Todd’s Cycl. Anat., I. 557/1. The Sepia … manifests … a near affinity to the Tetrabranchiate order.

2

1851.  Woodward, Mollusca, I. 78. The shell of the tetrabranchiate cephalopods is an extremely elongated cone.

3

1872.  Nicholson, Palæont., 189. The Tetrabranchiate forms, with chambered shells, attained their maximum in the … Silurian period.

4