78 L. Schwendler — Discharge of long Telegraph lines. [No. 1, 



pallida,— Burma, Thoungyeen, March, 1862. (Dr. Brandis).— This 

 species will range along with A. ochraceum, Dalz. 



LYQOPOVIAOEJB. 



108. Selaginella semicordatum, J. Scott, (in Journal of Agri- 

 Horticult. Society of India. New Ser., vol. I, part 2, p. 261 (1860) is 

 S. semicordata, Spring, Enum. Lycopod. No. 78 and Monogr. Ly co- 

 pod., II, 107 (Lycopod. Wall. Cat. 137). 



S. implexa, J. Scott, 1. c. p. 262, is identical with S. tenera, Spring, 

 Enum. Lycop. No. 144 and Monogr. Lycopod., II, 241. 



S. aristatum, J. Scott, 1. c. 262, founded apparently upon Lycop. 

 aristatum, Eoxb., in Maclell., Calcutt. Journal. Nat. Hist., IV, 473, 

 is unknown to me, and it is impossible to compare the plant with 

 any of Spring's diagnoses, Mr. Scott's description being insufficient 

 in several points. 



LEMNACEJE. 



109. Lemna tenera, n. sp. 



Frondiculse cruciatse, lanceolatae ad lineari-lanceolataa, ssepius 

 subcurvulse, acurninatae, basi magis minusve rotundatae, membra- 

 nacese, subtus (in viro) obsolete trinerves et reticulato-venosae ; 

 radiculse solitariae. — Frondiculae 3 — 4 lin. longse, basi lineam circi- 

 ter latee ; radiculse vix pollicares. 



Pegu, in jungle-swamps of Pazwoon doung valley, rare. 



Arrangement eor the discharge of long Overland Telegraph 

 lines, ly Louis Schwendler, Esq. 

 [Received 27th. January, 1871.] 

 When organizing more regular and instantaneous telegraphic 

 communication between the Presidency towns of India, and es- 

 pecially between Calcutta and Kurrachee, it was observed that 

 discharges occurred sufficiently strong to affect the relay of the 

 sending station, and giving rise to the so called " return beats." 

 These discharges* through the relay of the sending station are 



* It is well known that an overland telegraph line acts as a Leyden jar in 

 the same manner as a submarine cable, having, however, only a much smaller 

 capacity on account of the insulating layer (the air between the telegraph 

 wire and surrounding conductors) being very thick. But, though the capacity 



