322 Transactions. — Zoology. 



microscopically resemble those of P. paradoxum so closely as 

 to require no fm^ther description here. 



'J^he test differs from P. paradoxum in two important 

 points. First, the outer hyaline layer is far more extensive. 

 Secondly, the bladder-cells are only present irregularly beneath 

 it (fig. 7, hl.c), being few in number in the layer of test above 

 the cloa'cal canals, though numerous lower down. Each cell 

 in the upper groups is oval in outline (fig. 7). Vascular 

 appendages are common : they may be long and filamentous 

 (fig. 1), or short and club-ended (fig. 2, v-a^].). 



The zooids are much larger than in any species previously 

 examined, and occupy a relatively larger amount of the 

 common test. The abdomen is much larger than the thorax, 

 from wdiich it is separated by a short oesophago-rectal tube, 

 which exhibits a shght constriction below the point of origin 

 of the vascular appendage (figs. 1 and 2). So slight is this, 

 however, that it can scarcely with fairness be termed a con- 

 striction. , „. , ., T £ ■ .^ 



The branchial siphon (figs. 1 and 6) has its edges iamtly 

 six-lobed. Narrowest above, it dilates gradually to the circle 

 of tentacles, which are moderately long and of equal length. 

 Longitudinal muscular bands (fig. 6, l.b.m.) run down the 

 siphon from the oral lobes, gradually losing their distinctness 

 till they merge in the muscular wall above the buccal ten- 

 tacles. These longitudinal buccal inuscles are characteristic 



of the species. i • i i i j. 



Four rows of stigmata are present— the branchial basket 



seeming to resemble that of P. paradoxum very closely. The 



lamina transversahs is, however, reduced to a mere muscular 



The endostyle differs from that of its ally in being much 

 more undulating throughout its entire length. The peri- 

 pharyngeal band and nervous centre offer no theme for special 

 comment : both are distinct. No dorsal languets were ob- 

 served, but they undoubtedly exist. _ _ . m , ^ 



The alimentary tract (fig. 8) is a repetition of that of 

 P paradoxum; the figure serves equally well for both, ihe 

 upper half of the stomach has been cut away m sectioning, 

 showing the pecuHar shape of the cavity, with the passagesot 

 the oesophageal and pyloric tubes commencing. Only the 

 glandular part of the rectum is figured. Its upper mem- 

 branous portion does not cross the oesophagus, but passes 

 out directly to the atrial pore, which is provided with a long, 

 thick languet above and a well-marked projection below (fag. 



' ^The reproductive organs do not differ essentially from those 

 of P paradoxum. The testis consists of a number of spermatic 

 vesicles, — usually seven, but ten were found in one case, — 



