THE MARINE ALO/E OF NEW ENGLAND. 45 



Tho jionns is too nearly rt'latod to Chatomorpha, from wliicli it diiTtTH in siibstanco, 

 tlio lilauit'iits l»oing moro or los8 <;i'latinons in Ulothrix luxd ri;i;iil in Chatomorpha. Of 

 all the tilameutous marine Chloroi^ponw the species of Ulothr'u are best a<lai)te<l for tho 

 -tiuly of zoospores. Tho conjugation of zoospores in Uhthrix zonata, a fresh-water 

 »pecies, has heen very fully described by Dodel-Tort in Prinj^sheim's Jahrbiieher, 

 Vol. X. 



U. FLACCA, (Dilhv.) Tliiirot. {Li/nr/bya Jlavca aud Cannivhacliij Ilarv., 

 Pliyc. Brit., PI. 300 and 18(> d. — Ilormofrichum Cnrmlchadii, Ilarv., Ner. 

 Am. Bor., Part III, p. DO.) 



Filaments line, lubricous, greenish yellow, one to three inches Ion ^f, 

 at first tul'ted, then entangled and forming strata of indefinite extent 

 tilaments .Ol-i-30'""' in diameter, becoming moniliform, cells .003-12"^'" 

 long, generally narrow, discoidal. 



Eastport, Maine., on stones and Ehoihjmcnia^ August; Xahant, Mass., 

 Mr. Collins^ spring; Isles of Shoals, K. n., Mrs. Davis ^ Europe. 



A species most luxuriant in the sprinjj, but also found in summer. The form fotnid 

 at Eastport was the entangled stage which is connnon on wood-work at low-water 

 mark. 



U. ISOGONA, (Engl. Bot.) Thuret. (Conferva Youngana^Hdvy.^Vhyc. 

 Brit., PI. 328. — Lynghya spcciosa^ 1. c., PI. 180 h. — Ho r wot rich urn Youmj- 

 anunij^er. Am. Bor., Part III, p. Sd.— Uroftjwra pcnicilUformis^ Aresch. 

 in part.) 



Filaments fine, yellowish green, one to three inches long, at first 

 tufted, afterwards forming strata, filaments .030-58'""' in diameter, 

 moniliform, cells .015-50™'" long, from cuboidal becoming ovate, con- 

 striction at nodes marked. 



Xew York, Harvey; Ives Point, Conn., Mr. Hall; Gloucester, Mrs. 

 Davis; Xahant, Mr. Collins; Europe. Spring. 



Distinguished from the last by its greater size and by the marked constriction be- 

 tween the cells at ra.aturity. Apparently common on wood-work. Whatever name 

 we may give to this species, it is tho same form which is common in tho northern 

 !>art of Europe in spring aud summer. It is tho Hormofrichum Youngannm of British 

 authors, and the U. iaogona of the French. It is tho species referred by Areschoug, 

 (.►bsersationes Phycologicaj, II, Act. Reg. Soc. Scient., Ser. Ill, Vol. 9, to Conferva pen i- 

 dlUformis, Roth, and made by him the typo of tho genus Urospora. Areschoug unites 

 under the single species U. peniciUiformis tho following species of Phycologia Brit- 

 tanica: Lyugbya speciosa, L. Carmichaelii, L. Gutleria:, L. flaoca, and Conferva Youngana. 

 In the present case we have kept U. Jlacca and U. isogona distinct, but agree with 

 Areschoug in uniting U. ftpeciosa with U. isogona. Perhaps a further acquaintanco 

 with the species might lead us to unite tho present two species under Areschoug's 

 name. 



The Uormotnchum speciosum of Eaton's list of Eastport algic belongs to another 

 genus. The II. borcale, 1. c, is unknown to me. 



U. COLLABENS, (Ag.) Tluir. ? {Conferva collabenSjUiXTV., Phye. Brit., 



PI. 327. — Hoi-motrichiim collabenSy Kiitz., Spec. Alg., p. 383.) 



Filaments tufted, two to six inches long deep green, cells from .05- 



