83 



upward. On the rounded apex of the rays a .small apiculum is 

 to be found in these specimens. 



While these specimens occurred in shallow water growing 

 on small shells and stones on muddy bottom together with A. cre- 

 niilata, I have further found some very few individuals (Fig. 67) 

 in deeper water and as these specimens seem to show a few differ- 

 ences I shall describe them a little more in detail. The plants 

 were of intermediate size ; the largest I have seen had a disc about 

 8 mm. broad. The length of the stipe varies from 1 to 3 cm. ; 

 it is vigorous, rather thickwalled and has no spindle-shaped 

 swellings. 



The disc is flattened ; it has about 50 rather thinwalled rays 

 which are all firmly united even after treatment with acid. The 

 wedge-shaped rays end in a 

 rounded apex which often 

 quite lacks the small api- 

 culum (Fig. 68 A). The co- 

 rona superior and inferior 

 (Fig. 68 B and C) are of al- 

 most the same oblong — 

 cordate shape, with a rather 

 deep sinus in the end turned 

 outwards, deepest in the co- 

 rona inferior. Corona super- 

 ior has two hair-scars one 

 behind the other. 



Rather a large number 

 of gametangia (about 200) 



were found in the rays of one of the specimens ; they were about 

 60/>< broad, but I may mention that the plant was yet cjuite im- 

 mature ; the calcareous massula in which the gametangia ought to 

 be embedded I was unable to see in this specimen. 



This species was found: St. Croix, at Long Point most probably 

 in shallow water; St. Thomas: The Lagoon of Bovoni in shallow water; 

 St. Jan: Off Cruz Bay in about 30 meters depth (only one specimen 

 found), and off America Hill in about 16 meters depth (only two speci- 

 mens found). 



Geogr. Distrib. South America, West Indies. 



Fig. 68. Acicularia Schenckii (Mob.) Solms. 



A, ends of rays; B, Corona superior with 



hair-scars; C, Corona inferior. 



(A, 10:1, B and C, 60:1). 



