328 Natural History of British Zoophytes. 



Polypes de la seconde espece, Tremb. Mem. pi. 1, fig. 2, 5; pi. 2. fig. 2 ; 



pi. 6. fig. 2 and 8; pi. 8. fig. 1—7 ; pi. 10. fig. 1—7 ; pi. 11, 12, 13. 



figs. omn. partly copied in Adams, Micros. 399, pi. 21. fig. 6 Hydra 



vulgaris. Pall. Elench. 30. Ellis and Soland. Zooph. 9 H. grisea, 



Lin. Syst. 1320. Mull. Zool. Dan. Prod. 230, No. 2784. Verm. i. ii. 



14. lire's Rutherg. 233. Berk. Syn. i. 222. Turt. Gmel. iv. 692. 



Turt Brit. Faun. 218. Stew. Elem. ii. 452. Lam. Anim. s. Vert. 



ii. 60. Bosc, Vers ii. 275. Stark, Elem. ii. 443. Templeton in Mag. 



Nat. Hist. ix. 418 — H. brunnea, Templeton, loc. cit. 417. fig. 56 



First sort of Polype, Baker, Polyp. 17. c. fig L'Hydre commune, 



Blainv. Actinol. 495. 

 Hah. Weedy ponds and slowly running- waters. Probably com- 

 mon in all parts of the kingdom. 



On comparing the descriptions of the authors quoted above, I am 

 led to conclude that this species is either subject to much variety, 

 or that two species have been confounded together, and given rise 

 to a discrepancy which seems otherwise irreconcileable. My own 

 experience inclines me to the latter supposition, but since I have 

 had no opportunities of making- observations on specimens from dif- 

 ferent and distant localities, I deem it more prudent to indicate what 

 appear to be two species as only varieties of the vulgaris, until the 

 point can be settled by more leisured naturalists. 



Var. a. aurantia, light reddish-brown or orange-coloured ; tenfa- 

 cula not longer than the body. Plate X. Fig. 1. 



Var. h. grisea, light olive-green ; tentacula paler and longer than 

 the body. Plate X. Fig. 2. 



The first is by much the commoner, and does not exceed the H. 

 viridis in size, which it resembles also in its habits and form. It is 

 always of an orange, brown, or red colour, the intensity of the tint de- 

 pending on the nature of the food, on the state of the creature's re- 

 pletion, becoming even blood-red when fed upon the small crimson 

 worms and larvae which usually abound in its haunts.* The tenta- 

 cula in all my specimens have never exceeded the length of the body, 

 are usually seven or eight in number, and taper to the point insensi- 

 bly. Every part of the body is generative of young, which may fre- 

 quently be seen hanging from the parent at the same time in different 

 stages of their growth. Baker's figure represents this variety very well. 

 The second is a larger animal and comparatively rare, less sensible 

 to external impressions, and of a more gracile form. Its colour is a 

 dilute olive-green with paler tentacula, which are considerably longer 

 than the body, and hang like silken threads in the water, waving to 

 and fro without assuming that regular circular disposition which they 



* " 1 have found a bright red Hydra rather abundant on Putney Heath, near 

 London. It does not much difl^er, except in colour, from the green one." J. E. 

 Gray in lit. May 6, 1833. See Trembley's Mem. p. 47, and 128. 



