134 



material was scanty or the specimen sterile, I queried these 

 doubtful specimens and placed them near to the species which 

 they most resemble, leaving it to future investigators to decide 

 whether they are forms of the type - - or new species. 



One specimen belongs probably to the genus Cruoriopsis, but 

 it is in such incomplete state, that it cannot be identified with 

 certainty. 



Besides the easily known and doubtful species the collection 

 of Dr. B0RGESEN contains: 



two new Cruoriella, 



one new Peyssotmelia and 



one new Contarinia, of the family of the Rhizophyllidacese. 



Before giving the systematic list of the species, 1 may per- 

 haps add a few words to express my sincere thanks to Dr. BOR- 

 GESEN, for entrusting me with his collection and to Mr. HARIOT 

 of the Museum d'Histoire Naturelle de Paris, for his kind help 

 in sending me valuable specimens for comparison. 



Cruoriopsis Dufour. 

 1. Cruoriopsis spec. 



One of the small specimens in the collection of Dr. BORGESEN 

 carries at the top of the ascending filaments two short files of 

 moniliform cells of peculiar aspect; they remind one of the car- 

 pospores in the cystocarps of Cruoriopsis cruciata. The cells are, 

 however, still very young and I have seen no other organs of 

 fructification. I do not dare to name this alga with certainty 

 but I think it likely, that it is a member of the genus Cruo- 

 riopsis. 



Found at St. Thomas, in the harbour at the French Wharf. (N. 52). 

 Dry Specimen. 



Peyssonnelia Dec. 



Key to the subgenera and species of Peyssonnelia from the 

 West-Indian region, collected by Dr. F. BORGESEN. 



I. Thallus procumbent, more or less firmly adhering to 

 the substratum, orbicular or irregular in outline, with 

 a hypothallus consisting of dichotomous filaments, run- 

 ning from the centre towards the periphery and form- 



