THE MARINE ALG.E OF NEW ENGLAND. 163 



From Xew Haven northward. 



One of the more common Floridece north of Cape Cod, and not rare in the colder 

 ■waters of Long Island and Vineyard Sounds. It is found all the year, but especially 

 in the autumn and winter. It is at once recognized by the presence of a midrib and 

 lateral veins and by its general resemblance in outline to an oak-leaf. 



D. alata, Lam.x. ; Phyc. Brit,, PI. 247. 



Fronds two to four inches long, an eighth of an inch wide, stipitate 

 below, above pinnately decompound, divisions linear, margin entire, 

 costate, lateral veins scarcely visible ; tetraspores tripartite, borne in 

 the apices of the segments or in special leaflets ; cystocarps hemispheri- 

 cal, on the upper veins. 



Var. angustissima, Harv., Phyc. Brit,, PI. 83. 



Fronds very narrow, blade of the leaflets almost wanting. 



From Boston northward, with the last ; Europe. 



A common species of Northern New England, but not yet found south of Cape 

 Cod. Our form is uniformly narrower than the common European form, and there is 

 scarcely a trace of lateral veins. Hypoglossum Grayanvm, Reiusch, Contributiones ad 

 Algologiam et Fungologiam, p. 55, PI. 42, appears to be the same as D. alata of the New 

 England coast. 



D. Leprieurii, Mont,; Ner. Am. Bor., Part II, PL 22 e. {HypogJos- 

 sum Leprieurii, Kiitz. — Caloglossa Leprieurii, J. Ag., Epicr.) 



Fronds purple, one to two inches high, about a tenth of an inch wide, 

 dichotomous, articulato-coustricted, costate, proliferous from the costa, 

 segments linear-lanceolate, attenuate, rhizoids and new leaflets formed 

 at the constrictions ; tetraspores tripartite, in oblique lines extending 

 from the midrib to the margin ; cystocarps sessile on the midrib. 



West Point, Bailey ; Fort Lee, N. T., Mr. Averill ; Harlem River, 

 C. R. Peck; and common southward. 



This small species inhabits tidal rivers where the water is warm, and is found on 

 wood-work, stones, and water-plants. It is probably not rare near New York, and on 

 our Southern Atlantic coast it is common. It extends to the West Indies, and is also 

 found in the warmer waters of both hemispheres^ It is distinguished at once from 

 our other species by its small size, purple color, and very thin constricted fronds. 

 The species was placed by Harvey in the subgenus Caloglossa, which is separated as a 

 distinct genus by Agardh in his Epicrisis. 



GRAC1LAKIA, Grev. 



(From gracilis, slender.) 



Fronds filiform or compressed, carnoso-cartilaginous, dichotomous or 

 irregularly decompound, composed of an inner layer of large angular 

 cells, which become smaller outwards, and a cortical layer of small col- 

 ored cells; antheridia in cavities sunk in the cortex or superficial; 

 tetraspores cruciate, dispersed in the cortical layer ; cystocarps exter- 

 nal, sessile, spherical or conical, with a large cellular placenta at the 



