SYNASCIDIA. 



33 



Distaplia Delia Valle (Fig. 25), with a common cloaca and atrial languets, 

 incubatory pouch as diverticulum of cloaca, colony sessile or only shortly 

 peduncnlated ; Med., AtL, Ind. Ocean. Julinia Caiman, Antarctic. Dis- 

 toma Gartner, with atrial siphon, without, pinnies in th t.p=t-, and 

 incubatory pouch, 

 colony sessile or only 

 shortly pedunculated ; 

 Med., Eur., Torres 

 Straits. Heterotrema 

 Fiedler, Cystodites v 

 Drasche, Colella Herd., 

 with an incubatory 

 pouch and a well- 

 marked peduncle, S. 

 Ocean. Oxycornia v. 

 Drasche. Chondro- 

 stachys Macdonald, the 

 zooids project beyond 

 the test, Aust. Archi- 

 distoma Garstang, the 

 zooids arise from an 

 incrusting basal layer, 

 either singly or united 

 in a common test, with- 

 out common cloaca ; 

 covered with sand ; 

 may be compared to a 

 Glavelina in which the 

 tests of the zooids 

 have fused in groups ; 

 Plymouth. 



Finn. 3. Polyclini- 

 dae. Colony usually 

 massive, sometimes en- 

 crusting, sometimes 

 lobed or even stalked; 

 systems of various 

 shapes, sometimes ir- 

 regular or absent ; 

 common cloaca! aper- 

 tures usually indistinct 

 or absent ; zooids 

 placed perpendicular- 

 ly to surface, usually 

 divided into thorax, 

 abdomen, and post- 

 abdomen (Fig. 26) ; 

 mouth 6 or 8-lobed, 

 atrial aperture often 

 with atrial languet ; test sometimes stiffened by embedded sand grains; 

 pharynx small with small stigmata, without internal longitudinal bars, 

 with horizontal membranes ; tentacles small, few ; dorsal lamina as 

 languets; gonads in post-abdomen, testis as spermatic sacs attached to 



FIG. 26. Diagrammatic section through a portion of a Poly- 

 clinid colony (after Delage and Herouard). 1 openum of 

 common cloaca ; 2 atrial openings ; 3 ganglion ; 4 mouths ; 

 5 tentacles; 6 peripharyngeal band ; 7 endostyle ; 8 languets; 

 y anus; 10 male; 11 female generative opening; 12 epic;inli.i! 

 tubes; 13 stomach; 14 pyloric gland ; 15 ovary ; Ifi tr.-ti- : 

 17 epicardium ; IS dorsal; 19 ventral limb of pericardium ; 

 20 posterior bifurcation of epicardium ; 21 heart. 



Z III 



D 



