ASTERIONELLA. 



[ 84 ] 



ASTEROPHORA. 



of both Rotalia and Discorbina, that have 

 star-like patterns on one face of the shell. 

 In some Rotalice an astral arrangement of 

 subsidiary chamberlets around the umbo is 

 formed as in Amphistegina ; and in several 

 Discorbinte the deep radiating sulci around 

 the umbilicus are roofed over with distinct, 

 more or less perfect plates of shell. 



BIBL. Carpenter, Intr. For. 204, 213. 



ASTERIONELLA, Hass A genus of 

 Diatomaceae (Cohort Fragilarise). 



Distinguished by the inflation of one or 

 both ends of the frustules, and by the adhe- 

 rence of their adjacent angles into a stellate 

 form. 



Doubtless the frustules are originally 

 parallel, forming a straight filament. 



A.formosa (PI. 18. fig. 14). Frustules 

 4-8 ; in the front view somewhat more en- 

 larged at the attached than the free end. 

 Aquatic; length 1-384". 



A. Ralfsii. Frustules linear ; valves at- 

 tenuated towards one end, constricted to- 

 wards the other, which is rounded and capi- 

 tate. Aquatic ; length 1-555". 



A. Bleakeleyii. Frustules linear, enlarged 

 at the base. Marine ; length 1-454". 



2 other species. 



BIBL. Hassall, Micr. Exam, of London 

 Water ; Smith, Br. Diat. ii. 81 ; Greville, 

 Ann. N. H. 1865, xvi. p. 4 ; Rabenhorst, 

 Flor. Alg. i. p. 141. 



ASTERODIC'TYON, Ehr. (Per. d. Berl. 

 Akad. 1845). See MONACTINUS. 



ASTERODIS'CUS, Johnson. A genus 

 of fossil Diatomaceee, allied to Asterolampra 

 and Aster omphalos ; but distinguished by 

 one septum dividing halfway from the 

 centre, and proceeding to two of the com- 

 partments, the intermediate smooth ray 

 being smaller than the others. 3 species ; 

 rays from 5 to 9. 



BIBL. Johnson, SittimavCs Jn. 1852, xiii. 

 p. 33. 



ASTEROLAM'PRA, Ehr. A genus of 

 fossil Diatomaceas. 



Char. Free; circular; central portion 

 divided by thin septa, which do not reach 

 the margin, but alternate with rays extend- 

 ing to the margin, unsupported by septa ; 

 fossil. Intermediate between Actinocyclus 

 and Actinoptychus. 



A. marylandica (PI. 25. fig. 5). Marginal 

 rays eight, septa eight ; interstices between 

 the rays exhibiting elegant curved series of 

 dots ; diam. 1-180". Found fossil in Mary- 

 land. 



Other species. 



BIBL. Ehr. Ber. Berl Ak. 1844, p. 73 ; 

 Greville (Jfbnflpr.), Mic. Tr. 1860, p. 102, 

 1862, 41, 1863/227, 1865, 99; Kiitzing, Sp. 

 Alg. 129. 



ASTERO'MA, D.C. A genus of Sphse- 

 ronemei (Stylosporous Fungi) growing 

 upon leaves and stalks, forming very minute, 

 slightly prominent coloured or black spots, 

 more or less confluent, seated on more or 

 less distinct radiating filaments. Fries 

 separates part of the species under the name 

 of Actinonema. Species : 



A. reticulatum, D.C. JDothidea reticitlata, 

 Fr., Corda. On decaying leaves of Conval- 

 laria. Hooker, Br. Pi. ii. part 2. p. 288. 



A. ?7/?m,Klotsch. On elm-leaves. Hooker, 

 Br. Fl. ii. part 2. p. 289. 



A. Prunella, Purt. On green leaves of 

 Pnnwlla vulgaris. Hooker, Br. Fl. ii. part 2. 

 p. 289. 



A. Padi, Grev. On Prunvs Padus. 

 Hooker, Brit. Fl. ii. pt. 2. p. 289 ; Berkeley, 

 Ann. N. H. vi. 364, pi. 11. fig. 4. 



A. Rosa, Lib. On rose-leaves. Libert, 

 Tr. Linn. Soc. Paris, 1826 ; Berkeley, Ann. 

 N. H. vi. p. 364, pi. 11. fig. 5. 



A. tabes, Berk. Ann. N. H. vi. 364. pi. 11. 

 fig. 6. 



A. Veronica, Desm. Berkeley, Mag. Zool. 

 Sf Bot. i. p. 511. 



BIBL. Fries, Summa Vcget. Scan. 424. 



ASTEROM'PHALOS, Ehr. A genus of 

 Diatomacea3. 



Resembles Asterolampra, except that two 

 of the central septa are parallel, and one of 

 the marginal rays absent or almost oblite- 

 rated. 



The species occur in the Antarctic ocean ; 

 the diameter of the valves lies between 

 1-900 and 1-47". They are distinguished 

 by the number and direction of the central 

 rays. 



A. Darwinii. Central rays five, flexuous. 



A. Hookerii (PI. 25. fig. 2). Central rays 

 six, marginal five, straight. 



A. Rossii. Rays six, inflexed. 



A. Buchii. Rays six, straight. 



A. Beaumontii. Rays seven, inflexed 

 (PL 18. fig. 15). 



A. Humboldtii. Rays eight, straight. 



A. Cuvierii. Rays nine, straight. 



A. Brookii. Rays ten. 



BIBL. Ehr. Ber. d. Berl. Akad. 1844; 

 Kiitzing, Sp. Alg. 129. 



ASTEROPH'ORA, Dittm. A genus of 

 Sepedoniei (Hyphomycetous Fungi), com- 

 posed of minute fibrous plants, growing 

 parasitically upon dry blackened Agarics^ 



