936 RECORD OF CURRENT RESEARCHES RELATING TO 



specifically from those of the south of Eui'ope. The genus Bulhochcete, 

 in America as in Europe, has most representatives in the northern and 

 north temperate zone. 



New Genus of Chroolepidas .*— Dr. Eeinsch has detected a new 

 genus of algfe, to which he gives the name Acrohlaate, and which he 

 refers to the family of Chroolepidse, attached to small mussels 

 belonging to the genus Turritella, and to small stones, on the coast of 

 Buzzard's Bay, west of Cape Cod, North America. 



The individual plants are microscopic, and form small green 

 tufts, resembling at first sight an Ectocarpus, the larger plants being 

 copiously branched. The characteristic reproductive organs, agreeing 

 in their origin and the development of their cell-conteuts with the 

 conceptacles of Chroolepus, are always formed at the apex of the fila- 

 ments, the zoospores being produced in them. The mode of growth 

 of the filaments resembles that of Cladophora. "While at present 

 placed among the Chroolepidre, the author thinks it possible that the 

 discovery of sexual reproductive organs may hereafter show Acrohlaste 

 to form a connecting link between this family and the Phfeosporeaj. 



Fossil Algae belonging to the Verticillate Siphoneae.t — Munier- 

 Chalmas includes under this section of calcareous alga) all the Chloro- 

 sporefe comprised by Harvey in the family Dasycladca^, and all those 

 fossil genera related to Larvaria, Chjpeina, Poh/tnjpa, Acicularia, Dac- 

 tylopora, and Uteria, many of which have hitherto been mistaken for 

 foraminifera. The group includes more than fifty genera, mostly 

 found in the Triassic, Jurassic, Chalk, and Tertiary formations. It is 

 at present represented only by seven living genera, viz. Dasycladus, 

 Halicorijne, Oijniopolia (including Polytrypa and Descaisnella), Poly- 

 physa, Acetahularia, Neomeris, and BorneteUa ; the last a new genus 

 founded on Harvey's Neomeris nitida, distinguished by the origin 

 of the sporangia at the side of the radiate threads, instead of at the 

 apex in the centre of the terminal pileus. 



The frond of the verticillate Siphonea) is simple or dichotomous, 

 formed of a tubular axis, from which spring successive whorls of 

 radiating branches. In many species the axis as well as the rays have 

 their wall encrusted with calcium carbonate, so that the plant is 

 enclosed in a calcareous envelope, which reproduces with exactitude the 

 details of its organization. This inorganic envelope consists of one or 

 two calcareous cylinders. The inner one is formed of the axis and the 

 first member of the verticillate rows of cells which spring from it. 

 The outer cylinder is composed of the outermost cells of the branches 

 which end in an enlarged swelling, the lateral margins coalescing 

 with those of the neighbouring ones. The fructification may also be 

 encrusted with lime, and contribute to the formation of the outer 

 cylinder, as may be seen in the genus Gymopolia. The fructification 

 sometimes consists of single receptacles or sporangia, as in Gymopolia 

 and Neomeris, sometimes of a number of smooth shining hollows in 

 which sporangia or spores are formed, as in Acicularia, Maupasia, Dac- 



* 'Bot. Zeit.,' xxxvii. (1879) p. SCI. 



t 'Comptes Rendus,' Oct. 29, 1877; see 'Bot. Zeit.,' xxxvii. (1879) p. 165. 



