316 ' ENDEAVOUR " SCIENTIFIC RESULTS. 



? Aglaophenia crucialis, Lamouroux, Hist. Polyp. Cor. Flex., 

 1816, p. 169. 



A. macrocarpa, which is not represented in the " Endea- 

 vour " collections, has been mentioned in Part I. for the 

 purpose of discussing its relationship with the other members 

 of the crucialis-gToup A. dannevigi, A. billardi, A. tasmanica, 

 and A. crucialis. I have since received some further material 

 including, from Mr. Briggs, fragments of specimens considered 

 to be A. crucialis, and others of A. macrocarpa, with drawings 

 of the latter and notes on the Museum specimens ; and from 

 Dr. Ritchie, mounted specimens of the " Thetis " form figured 

 by him as A. crucialis. 



A specimen from Maroubra Bay, forwarded by Mr. Briggs, 

 is a typical A. macrocarpa, agreeing with my former examples 

 in all essentials ; the gonosome is not present. I have 

 figured in Part I. portion of a specimen in the Australian 

 Museum, and Mr. Briggs has favoured me with drawings of 

 another and much more perfect specimen, which is of precisely 

 similar habit, the stem and branches being thick, and the 

 latter curving upwards and even inwards towards the ends, 

 while standing well out in front from the stem, towards which 

 they face. Other specimens differ a good deal in habit, the 

 hydrocaulus being more slender and the branches straighter ; 

 such a form is that figured by Ritchie, which, however, as 

 Mr. Briggs informs me, has the branches facing back towards 

 the stem or parent branch from which they spring, just as 

 in the typical A. macrocarpa. The hydro thecae differ from 

 that form only in being slightly larger and in possessing the 

 intrathecal tooth, which is sometimes strongly developed ; 

 its absolute inconstancy, however, in A. billardi and A. 

 tasmanica shows it to be a negligeable character in distinguish- 

 ing the species. The lateral lobes of the border are well 

 developed, and in some cases they tend towards an angular 

 form instead of being smoothly rounded as usual. 



The affinity between A. macrocarpa and A. tasmanica is 

 very close, and this is especially evident now that the male 

 corbulae of the two are known to be of similar type, (unlike 

 those of A. billardi). Which of these forms (if either) is to be 

 referred to A. crucialis is doubtful, since we are not informed 

 which of them it resembles in habit, nor what is the character 

 of its corbulae. 



AGLAOPHENIA BILLARDI, Bale. 



Aglaophenia billardi, Bale, Biological Results " Endeavour," 

 ii., 1, 1914, p. 33, pi. iii., fig. 3, pi. vi., fig. 3. 



