ACANTHASCUS CACTUS. 143 



or otlierwise somewhat outwards. Sometimes the body expands 

 superiorly in such a manner that it presents a funnel-like shape. 

 The sponge stands either erect Irom the basal attachment or is 

 hent more or less in the basal part. Laterally it is frequently more 

 or less distinctly compressed, especially in the basal region ; but 

 the upper part is about as often simply roundish or irregularly 

 roundish in cross-section. 



The wide and deep gastral cavity extends close to the infer- 

 ior end, so that the blind wall presenting the irregularly shaped 

 surface of basal attachment is not thicker than the adjoining 2;)art 

 of the lateral wall. This is on the whole only moderately thick, 

 gradually thinning above towards the thin and simple-edged 

 oscular margin. 



While many specimens represent pure and simj)le individuals, 

 each being in jDOSsession of a single large osculum at the superior 

 end, others show complication in that they consist of a main 

 j)erson bearing one, two or sometimes more, generally much smaller 

 daughter persons secondarily produced by budding. The bud is at 

 first a blind-sac-like outbubino; of the wall, which eventuallv 

 opens an osculum at the top. The oscular rim is for some time 

 closed inwards but may flare out later. The bud-formation seems 

 to be confined to the basal region, or at any rate to the lower 

 half of the mother body. Text-figure 6, A, represents a case in 

 which two persons, one somewhat smaller than the other, arise 

 side by side from a common basal part. The specimen shown in 

 C\ same figure, Ijears three buds : two on the convex sagittal edge 

 of the bent l)asal region, and one on the lateral side. Several 

 cases have been encountered of specimens similarly bent at base 

 and bearing on the convex side a single bud directed in the 

 opposite direction from the main part of the mother sponge, the 



