Howe: Phycological studies 79 



Later descriptions by other writers, also, have been based, in 

 part, at least, on specimens agreeing with the true N. dumctosa in 

 having mutually free sporangia but differing in various other 

 particulars. 



Just as the lateral coherence of the sporangia by their cal- 

 careous capsules forms a reliable and easily applied test for distin- 

 guishing Ncovieris annulata from N. dumctosa and its near allies, 

 so the similar coherence of the primary branches of the true 

 Neoiiicris dumctosa by intercalated lime-deposits constitutes an ap- 

 parently constant and reliable character for distinguishing the 

 species from others which have hitherto been identified with it. 

 This coherence was recognized by Lamouroux in his original 

 description by the words " inferne squamosa" and " ecailles 

 presque cuneiformes " and was emphasized by Cramer in his first 

 description, but has been generally ignored by subsequent writers. 

 This character is well illustrated by Cramer [pi. 2. f. ij), his 

 figure showing the calcareous scale perforated by the tubular 

 branches, with the width of the connecting lime-masses commonly 

 three or four times the diameter of the branches. Another pecu- 

 liarity of the true Neomeris dumctosa is found in the very caducous 

 nature of these scales. As Lamouroux well said, " le moindre 

 frottement les arrache du tube membraneux qu'elles laissent alors 

 a nu." In allied species which have been confused with N. dumc- 

 tosa, the individually separate primary branches are persistent. 

 Furthermore, the mature plants of N. dumctosa are more slender 

 and more taper-pointed than those from the Friendly Islands, the 

 Dutch East Indies, and Hawaii, which have hitherto been identified 

 with it. 



Neomeris dumctosa is said to have been brought from the 

 Antilles by Richard and there is as yet no sufificient ground for doubt- 

 ing the accuracy of this statement in spite of the facts that it appa- 

 rently has not since been collected in American waters and that some- 

 thing practically identical (except for smaller spores) has recently 

 been brought from the East Indies by Madame Weber- van Bosse. 

 Neomeris Cokcri is common enough in the Bahamas (we have it 

 from fourteen stations and have seen it often when not collected), 

 but the species has not yet been reported outside of this group of 

 islands. Neomeris mucosa, described as new in the present paper, 



