DIPPING-TUBES. 



[ 213 ] 



DISSODON. 



jugation has taken place ; they are yellow, 

 with the shell narrowed and prolonged into 

 a spiral or coil. 



BiBL. Nordraann, JMikrogr. Beitr'dg. 1832. 

 i. p. 56, Ann. d. Sc. nat. 1833. xxx.; Ehren- 

 berg, Wiegmann's Arckiv, 1835, ii. p. 128 ; 

 ]Mayer, Beitr'dg. z. Anat. d. Entoz. p. 23 j 

 Siebold, Sieb. and Kolliker'' s Zeits. f. Wis- 

 sensch. Zool. iii. p. Q2 ; Vogt, MuUer's Ar- 

 chiv, 1841. p. 33. 



DIPPING-TUBES. Intr. p. xxi. 



DISCELIACE^.— A family of operculate 

 Acrocarpous Mosses, of gregarious habit, 

 very dwarf and stemless, arising from a green 

 prothallium s])reading on the ground. The 

 sheathing leaves are appressed, oblong, acu- 

 minate and nerveless, composed of cells lax 

 at the base and apex, rhomboidally paren- 

 chymatous, destitute of chlorophyll, fusces- 

 cent and empty. The capsule is subglobose 

 and inclined, with a short collum, annulate 

 and long- stalked. The antheridial and ar- 

 chegonial flowers are upon the same runner 

 of the prothallium. British genus : 



DISCELIUM, Brid.— Calyptra longish, 

 very narrow, split almost to the summit, 

 wider in the middle, with the margin involute 

 on each side at the base. Peristome simple, 

 of sixteen lanceolate teeth, fissile in the 

 middle, trabeculate, striate, cai'tilaginous, 

 reddish or orange. 



Discellum nudum, Brid. =PFemfa nuda, 

 Hook. 



DISCELLA, Berk, and Br. — A genus of 

 Melanconiei(Comomycetous Fungi), forming 

 scattered, disk-like, dark spots upon twigs; 

 at first covered by the epidermis, which after- 

 wards splits and separates. Five species are 

 described, occurring on the willow, lime, 

 plane, and elder. 



BiBL. Berk, and Broome, Ann. Nat. Hist. 

 2 ser. v. 376. pi. 12. fig. 8. 



DISCOCEPHALUS, E.— A genus of In- 

 fusoria, of the family Euplota. 



Char. Head distinct from the body; hooks 

 present, but neither styles nor teeth. 



D. rotatorius (PI. 23. fig. 44). Hyaline, 

 flat, rounded at each end; head narrower 

 than the body; length 1-380". Found in 

 the Red Sea. Imperfqctlv examined. 



BiBL. Ehr. Infus. p. 3/5. 



DISCOMYCETES.— The name of one of 

 the families of Fungi under Fries's classifi- 

 cation, including the Helvellacei and 

 Phacidiacei of the Ascomycetes. 



DISCOPLEA, Ehr.— A genus of Diato- 

 maceae, not now retained. 



DISCOSIA, Libert. — A genus of Sphsero- 



nemei (Coniomycetous Fungi), probably re- 

 lated to some of the Sphcerice, as stylosporous 

 forms. The species have been' described 

 under various names, and the genus Phlycti- 

 dium of Notaris is synonymous with it. The 

 British species recorded seems to have 

 been greatly confused by difi'erent writers, 

 for the Discosia ainea, Libert, found on the 

 leaves of alder and heech= Sphceria artocreas, 

 Tode, Xyloma fagineum, Pers., Phlyctidium 

 nitidum, Wallr., Ph. clypeatum, Notaris; and 

 from its name we conclude also the Dothidea 

 alnea, Pers. of Hook. J5n7. Flor., with its 

 synonymes. Fries, in his Summa Veg., gives 

 -D, artocreas, alnea, and clypeata as three 

 distinct species. 



BiBL. Leveille', ^«w. des Sc. nat. 3 ser. v. 

 286 ; Fries, Summa Veget. 423 ; Fresenius, 

 Beitr. z. Mycol. Heft i. p. 66. pi. 8 ; De 

 Notaris, Mem. Acad, di Torino, ser. 2. x. 

 (1849); Berk., Hook. Brit. Flor. p. 278. 288. 



DI8ELMIS, Duj. ^ Chlamidomoxas, 

 Ehr. {Chlamidomonas pulvisculus, l^.z=.Di- 

 selmis viridis, D.; PI. 3. fig. 2. b, c; PL 23. 

 group 30). See Protococcus. 



Dujardiu describes a marine species, D. 

 marina. Body almost globular, obtuse, and 

 rounded in front, granular within (and from 

 generic characters), with a non-contractile 

 tegument, and two similar cilia. 



He adds to this genus, D. Dunalii:=Mo- 

 nas Dunalii, Joly, giving rise to the red 

 colour of the reservoirs of the salt-works of 

 the Mediterranean ; oval or oblong, often 

 constricted in the middle ; colourless when 

 young, gi-eenish when older, red when 

 adult; no eye-spot. Probably some marine 

 Algae. 



BiBL. Dujardin, Lifus. p. 340; Jol}', Hist, 

 d'un Petit Crust ace, ^-c. 1840. 



DISOMA, Ehr. — A genus of Infusoria^ of 

 the family Enchelia. 



Char. Body double, not ciliated ; mouth 

 without teeth, ciliated and truncated. {=En- 

 chelys with a double body.) 



D. vacillans (PI. 23. fig. 45). Segments 

 clavate, filiform; hyaline and narrowed at 

 the anterior end; length 1-380 to 1-288". 

 In the Red Sea. 



BiBL. Ehr. hif. p. 302. 



DISSODON, Grev. and Arnott. — A genus 

 of Splachnacese (Acrocarpous operculate 

 Mosses), including some Splanchna of 

 authors and a Cystodon. 



D. Frohlichianus, Grev. and Arnott = 

 Splanchnum Frbhlichianum, Hedw. 



D.splanchnoides,GYev.andAi'n.=.CysfodGn 

 splanchnoides, Br. 



