The Actiniae of the Plate Collectiou. 223 



valid generic character and that there may be, therefoi-e, iio necessity 

 for the genus Halianfhella, it is not impossible that it will be ne- 

 cessary to take Andres' term as the correct designation for the 

 forms with a mesogloeal sphincter. Until, however, Halcampella 

 endromitafa is examined as to the nature of its sphincter it is ad- 

 visable to retain Kwietniewski's HalianfJms. 



1. Halianthus chilensis n. sp, 



No. 499. Calbuco. 1 specimen. 



The Single individual (PI. 14, Fig. 1) of this species which was 

 collected was rather slender, measuring about 1,0 cm in length with 

 a diameter of 0,3 cm at the broadest part of the column. This 

 was covered throughout the greater part of its extent by a thin 

 brownish cuticle to which particles of foreign matter (diatom frus- 

 tules, etc.) were adherent. The Investment was, however, lacking 

 over a small portion of the column immediately proximal to the 

 tentacles, this naked region probably representing a capitulum. The 

 proximal end of the body was rounded and a little to one side of 

 the centre there was a distinct depression, appearing like the opening 

 of a pore, though sections showed that it was really due to a slight 

 invagination (Fig. 2) which may possibly represent a retracted physa. 



Not far from the rounded extremity a slight but distinct groove 

 surrounded the column and this might be regarded as the delimi- 

 tation of a scapus and physa, but the facts that the cuticular co- 

 vering extended as far down as the opening of the invagination 

 and that the mesogloea of the invagination was much thinner than 

 that of the rest of the column seem to indicate that the first sup- 

 position is more correct. If so, then the column shows a distinction 

 into capitulum, scapus and physa, the first and last of these regions 

 being relatively small and the physa capable of retraction. No pores 

 could be discovered in the pliysal region. 



The tentacles were twenty-four in number, arranged in two 

 cycles, and were rather slender and acuminate, though short. The 

 disc was elevated into a distinct cone at the apex of which was the 

 mouth; no gonidial grooves could be distinguished. The disc was 

 thin and translucent aud of a paler brown than the column and 

 tentacles. 



Structure. The mesogloea of the column wall was on the 

 average but little thicker than the ectoderm, but it varied consi- 

 derably in thickness in different parts of the same section owing 



