Allman, A Monograph of the Gymnoblastic or Tubularian Hydroids (Ray Society, 1871-1872).
Allman, "A Monograph of the Gymnoblastic or Tubularian Hydroids," Ray.
Allman, " A Monograph of the Gymnoblastic or Tubularian Hydroids," Ray Society (1871-1872); 2.
The gymnoblastic polyp usually has a distinct perisarc investing the hydrorhiza and the hydrocaulus, sometimes also the hydranth as far as the bases of the tentacles (Bimeria); but in such cases the perisarc forms a closely-fitting investment or cuticule on the hydranth, never a hydrotheca standing off from it, as in the next sub-order.
- Diagram showing possible modifications of persons of a gymnoblastic Hydromedusa.