191 Ros 



Rigid. — Hard, which does not bend or yield to 

 pressure ; stiff, not pliant ; inflexible, (L. 

 rigeo, to be stifE.) 



Rimose, Rimous. — Chinky, resembling the bark of 

 a tree. Having a number of minute, narrow, 

 and nearly parallel excavations, which run into 

 each other. (L. rimosus, from rima, a cleft.) 



Rivose.— When furrows do not run in a parallel 

 direction, and are rather sinuate ; marked with 

 sinuate furrows, (L. rivus, a stream.) 



Rod (of the eye).— [See Khabdom.] 



Rorulent. — Like dew-drops, (L. ros, roris, dew.) 

 See Polinose, and Pulverulent. 



Rorulent. — Covered with a bloom, like that of a 

 plum, which may be rubbed off. (L. rorulentus, 

 from ros, roris.) 



Rosaceous. — ^(Scent.) A smell of roses. (L. rasa, 

 a rose.) 



Roseous, Roseus.— Rose colour. (L. rosa.) 



Rostellum. — The oral instruments of Pediculus, 

 and some other Aptera, in which the ordinary 

 trophi are replaced by an exarticulate retractile 

 tube, which controls a retractile siphuncle. 

 It includes the tubulus, and siphunculus. 

 (From L. rostrum, a beak, mouth.) 



Rostral filaments. — The four hair-like processes 

 which together form the sucking-tube or 

 sucking mouth of the Coccida). (L. rostrum, and 

 filmn, a thread.) 



