POLYZOA HYPPOCREPIA. 



FAMILY— CRISTATELLIDiE. 

 30. Crist ATELLA,*" Ouvier. 



Character. — " Polypidom free., contractile, locomotive. Po- 

 lypes issuing from apertures arranged upon the upper surface; 

 tentacular disc crescentic. Ova with marginal spines.'''' All- 

 man. 



]. C. MUCEDO. Sir John Graham Dalyell.*f- 



Plate LXXIII. 



De kleine Vederbos-polj'p, met het balvormig h'f, Rosel Hist, der Insect, iii. Polyp. 

 517, pi. 91. — Cristatella mucedo, Cuv. Reg. Anim. iii. 296. Gervais in Ann. des 

 Sc. Nat, Part. Zool., vii. 77, n. s. Turpiti in ibid. vii. 65, pi. 2 and 3, fig. 1 — 7. 

 AUma?i in the AthenEeum, Sept. 1846, p. 1005. — C. vagans, Lam. Anim. s. Vert. 

 ii. 97., 2de edit. ii. 110. Blainv. Actinolog. 489 and 678, pi. 85, fig. 7. Bosc. 

 Vers, iii. 180, pi. 30, fig. 9. Siark Elem. ii. 442.— C. mirabilis, Dalt/ell in Edin. 

 new Phil, Journ. xvii. 414 ; and in Rep. Brit. Assoc, an. 1834, 604. 



Hab. " An inhabitant of the fresh waters of Scotland," Sir J. G. 

 Daly ell. And of those of Ireland, Professor Alhnan. 



" Perfect specimens occur from six lines to twenty-four in length, 

 by two or three in breadth, of a flattened figure, fine translucent 

 green colour, and fleshy consistence. Some of the shorter, tending 

 to an elliptical form, may be compared to the external section of an 

 ellipsoid ; but those of the largest dimensions are linear, that is, with 

 parallel sides and curved extremities." " The middle of the upper 

 and the whole of the under surface are smooth; the former some- 

 what convex, occasioned by a border of 70 or 80, or even of 350 

 individual polypi, disposed in a triple row. Their number depends 



* The diminutive of cristata, crested. 



+ The author of a very interesting work on the Planarise, and of some very 

 important researches into the physiology of the aquatic invertebrate animals in general, 

 the fuller publication of which naturalists expect with impatience. Sir John is the 

 translator also of some of Spallanzani's works ; and by other learned works he is well 

 known to antiquaries. 



c c 2 



