RESERVOIRS. 



[ 655 ] 



RHABDOSTYLA. 



single, pseudopodia arising from the postero- 

 ventral surface. R. caudata-, in hay-infu- 

 sions, and decaying grass 5 length 1-1000". 

 (Kent, Inf. 223.) 



RESERVOIRS FOR SECRETIONS 

 IN PLANTS. See SECRETING ORGANS of 

 Plants. 



RETE MUCOSUM. See SKIN. 



RETEP'ORA, Lamk. A genus of In- 

 fundibulateCheilostomatous Polyzoa, family 

 Escharidae. 



Char. Zoary leafy, reticular, fragile ; cells 

 on one surface only, short, and not promi- 

 nent. Two British species : 



R. reticulata. Wavy and convolute, upper 

 side warty and very porous. 



R. Bcaniana. Umbilicate, funnel-shaped, 

 wavy; interspaces unarmed. 



BIBL. Johnston, JBr. Zooph. 353 ; Gosse, 

 Mar. Zool. 18 ; Hiucks, Polyzoa, 388. 



RETICULA'RIA, Bull.' A genus of 

 Myxomycetes (Gasteroniycetous Fungi) 

 characterized by the indeterminate, thin 

 simple peridium, bursting irregularly, with 

 the branched, shrubby, reticulated capilli- 

 tium adherent to it. Several species are 

 British ; they are rather large plants, grow- 

 ing over recently felled timber or on hollow 

 trees, rails, &c., with great rapidity. 



BIBL. Berk. Sr. Fl. ii. pt. 2. 308 ; Fries, 

 Sum. Veg. 449 ; Syst. My col. iii. 83. 



RETICULA'RIA, Carpenter. Rhizo- 

 poda with long slender pseudopodia, which 

 meet and reticulate : as in Lieberkuehnia, and 

 other FORAMINIFERA. 



BIBL. Carpenter, Introd. For. 28; Mici-o- 

 scope, 476. 



RETINA. See EYE. 



RHABDAM'MINA, Sars. A relatively 

 large Arenaceous Foraminifer, usually tri- 

 radiate, but sometimes with four or even 

 five hollow rays or tubes, and sometimes 

 consisting of only the central chamber elon- 

 gated on two sides, forming one tube swollen 

 in the middle. R. abyssorum, Sars, At- 

 lantic and Pacific ; R. linearis, Brady, West 

 Indies and South Atlantic, at great depths. 

 (Carpenter, Soiree, Mic. Soc. 1870, 5 ; Brady, 

 Jn. Mic. Sc. n. s. xix. 37.) 



RHABDI'TIS, Duj. See ANGUILLULA. 



RHABDOGO'NIUM, Reuss. A three- 

 or four-angled Orthocerine Foraminifer. 



BIBL. Reuss, Sttz. Ak. Wien, xliv. 367. 



RH ABDOLITH ES, Schmidt. Minute, 

 subcylindrical, calcareous bodies, about 

 1-3000" length, usually consisting of a rod 

 and a terminal circlet of smaller rods 

 (1-25000"), simple or confluent. Abundant 



with coccoliths in the mud of the Adriatic ; 

 and fossil with the same in the chalk of 

 Manitoba and Nebraska. Found also in the 

 ocean-ooze by W. Thomson, and referred 

 by him to small floating spherules (possibly 

 vegetables) formed by their attached bases, 

 and termed by him Rhabdospheres. (Schmidt, 

 Sttz. Ak. Wien, Ixii. 669, and Ann. N. H. 

 4. x. 369 j Dawson, Canad. Nat. vii. 256 ; 

 W. Thomson, The Attlantic, i. 221.) 



RHABDONE'MA, Kiitz. A genus of 

 Diatomacese. 



Char. Frustules tabular, depressed, com- 

 pound, fixed by a stalk arising from one of 

 the angles, with interrupted vittae (front 

 view), vittas capitate ; valves transversely 

 striate, striee extending into the front view, 

 and forming numerous longitudinal series. 



Marine; upon Algae. Striae visible under 

 ordinary illumination ; the dark lines or 

 yittae correspond to more or less complete 

 internal septa; frustules connected with 

 each other by gelatinous cushions (isthnii). 



Conjugation and the formation of sporan- 

 gia have been observed. 



R. arcuatum (Striatella arcuat., Ralfs) 

 (PI. 17. fig. 18). Vittae in two marginal 

 rows, isthmi convex. Length 1-300''. 



R.minutum (Tessella catena, Ralfs). Vittaa 

 in two marginal rows ; transverse striae faint. 

 Length 1-1200 to 1-960". 



R. adriaticum. Vittae forming four rows 

 (interrupted in the middle, and again 

 between the middle and the margin on each 

 side) ; transverse striae distinct ; isthrni con- 

 cave. Length 1-480 to 1-170". 



BIBL. Kiitzing, Bacill. 126. and Sp. Ala. 

 115 ; Ralfs, Ann. N. H. xi. 455, and xii. 

 104 ; Smith, Diat. ii. 32 ; West, Micr. Jn. 

 1858, 186; Arnott, Micr. Jn. 1858, 91: 

 Rabenht. Alg. i. 305. 



RHABDOPLEU'RA, Allman. A genus 

 of Polyzoa according to Allman, and of 

 Hydroida according to Sars. Zoary tubular, 

 creeping or incrusting, septate, annulate, 

 bodies with an oral disk. It connects the 

 two classes, and presents many features of 

 great interest. Allman considers that its 

 polypary resembles that of the Graptolites. 

 Two species, on shells from deep water. 



BIBL. Allman, Qu. M. Jn. 1874 ; Sars, 

 Qu. M. Jn. 1874, 23 j Lankester, Qu. Mic 

 Jn. 1874, 77; Hincks, Polyz. 577. 



RHABDOSTY'LA, Kt. A genus of 

 Peritrichous Infusoria. Solitary, like Vorti- 

 cella, but with a rigid, short pedicle. Seven 

 species; salt or fresh water. (Kent, Inf 

 664.) 



