MELICERTAD/E. 83 



CE. BRACHIATUS, HttdsOU, sp. 110V. 



(PL IX. fig. 2.) 



[SP. CH. Corona distinctly tivo-lobed ; ventral antennae as long as the transverse 

 diameter of the corona, mobile, non-retractile; tube gelatinous, quite transparent, but 

 for adhering matters, subcylindrical. 



The front in retraction is rounded, ending in two geminate booked points. The 

 ventral antennae rise from swollen bases wide apart, and diverge on each side nearly in 

 the line of the body. They move independently of each other, often quickly, but not 

 spasmodically. In each can be seen a globose corpuscle within the tip, bearing one 

 seta, whence a double line (probably a tube or a nerve-cord of sensation) can be traced 

 throughout. A mastax of normal form, a long oesophagus, an ample stomach, and a 

 distinct intestine, are plain ; from this last a long up-turned rectum leads to the cloaca, 

 at half body-length. Laid eggs, of very long-ovate form, are usually seen, from one to 

 four in number, in the middle part of the tube. 



Below the viscera the body suddenly becomes hyaline, and gradually tapers to a 

 slender foot, twice as long as the body, through which run many pairs of muscle- 

 threads. At the bottom, already much attenuated, it abruptly contracts to an exces- 

 sively fine thread, which adheres by a sucking disk to the base. The investing tube is 

 wide and high, but is absolutely invisible ; and can be inferred only from a crowd of 

 minute diatoms (almost wholly of one slender kind) that are entangled in its substance. 

 The cavity of the tube can be easily traced, of equal width throughout, a width deter- 

 mined by that of the body, which, however, rarely retracts sufficiently to enter it. The 

 foot generally displays few transverse wrinkles. 



It is not reluctant to display its discal beauties. The corona is that of a Limnias, 

 composed clearly of two circles united ; the dorsal gap wider than the ventral. Each 

 half is conspicuously marked with a thick rib (muscle or vessel ?) originating in the 

 common centre, and divaricating, with many branches, nearly to the circumference. 

 But, just within the margin, a concentric band connects these branches, forming a sub- 

 marginal edge, thick and dark, which is constantly thrown into varying puckers by 

 contraction ; the whole contributing greatly to the beauty of the corona. 



This species, which is among the finest of Rotifera, was discovered in 1882 by Mr. 

 John Hood of Dundee, to whose successful researches this work bears grateful witness. 

 He obtained it from several lochs around ; and sent a specimen (which did not survive 

 the journey) to Dr. Hudson, with many notes and sketches. Recently he has favoured 

 me with many specimens, which have freely increased in captivity with me, even in 

 very small phials, so as to be swarming, by scores, for months after their transmission. 

 Thus I have had abundant facilities for study and delineation of the species. It has 

 always occurred attached to filamentous weeds much crowded with impalpable algae. 



Length, t l inch to ^ z inch. Habitat. Weeds in Scottish lochs (J.H., P.H.G.) : 

 not rare.— P.H.G.] 



(E. (?) velatus, Gosse. 

 (PL D. fig. 8.) 



Mcgalotrocha vclata . . . Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 198. 

 Melicerta ptygura (?)... ,, Papular Sci. Rev. vol. i. 1802, p. 190, pi. xsvi. fig. d. 



[SP. CH. Corona very large, circular, crossed by thick diverging ribs; teeth four 

 in each ramus; eyes tii-o, cervical, permanent; tube habitually wanting. 



This very beautiful form is aberrant, if indeed it is an CEcistes. My attempts to 

 assign it, first to Mcgalotrocha and then to Ptygura, must both be given up. The 



