692 



SYSTE:HATIC history of the rNTUSORIA. 



hooked at the end ; on the inside is an 

 aculeate process and a ridge to which 

 strong striated muscles, working the 

 jaws, are attached. (Esophagus long, 

 its lower end highly musciilar ; two 

 spherical glands open into the round 

 yellowish-brown stomach (32 b) ; intes- 

 tine absent. Walls of the contractile 

 vesicle (32 e), which open into the 

 cloaca, with a muscular network. Two 

 water-vascular canals on each side, one 

 with granular walls, the other wider and 

 with about fifty tags (31 & 32). Cere- 

 bral ganglion laid across the maxillary 

 bulb, with a dark-red or black speck 

 above and behind it in the median 

 line. Cells of the ganglion, according 

 to Leydig, fusiform, and prolonged into 

 nervous cords. A nerve is said to pro- 

 ceed from each side to the setigerous 

 fossa of the rotary organ, where it swells 

 out like a ganglion ; another nerve, from 

 its posterior surface, divides to supply the 

 smaller eminences on the rotary organ ; 

 and another pair from the same sur- 

 face supply the smaller eminences : but 

 we think these supposed neiwes require 

 re-examination. Ovaiy horseshoe-shaped 

 (32 c). Male and female young never si- 

 multaneously generated within the same 



parent. Winter eggs (xxx"^t:i. 27, 28) 

 spherical, usually one or two, never more 

 than three ; yelk yellowish-red, invested 

 by a thin membrane, which in turn is 

 surrounded by a thick granular tuber« 

 culated shell, the latter rendered pale 

 by potash, which partly obliterates the 

 tubercles. On keeping specimens in pure 

 water without nomishment, all the ego-s 

 deposited were winter ova. Males differ 

 in figure (iig. 29) from females : clavate, 

 with four conical arms ; the two anterior 

 ones (29 a) the smallest. When swim- 

 ming, which it does on its back, these 

 arms are shortened. Rotary, muscular, 

 and nerv'ous structures as in the females^ 

 Pyriform testicle (29 c) next the con- 

 tractile sac, filled with spermatozoa, 

 amongst which are round vesicles, nu- 

 cleated fusiform bodies (30 b, c), cun^ed, 

 nucleated, sickle-shaped objects (30 a), 

 and stiff, sharply-defined rod-like bodies 

 (30/). Duct on the abdominal surface 

 at the end of the body, and surrounded 

 by what look like accessory glands. 

 Alimentary canal absent ; the rudimen- 

 tary digestive organs represented by an 

 irregular heap of cells behind the pos- 

 terior anus. Yoimg males born alive. 



Genus TAPHROCAMPA (Gosse). — Rotary organ wanting, body fusiform, 

 annulose ; tail forked ; gizzard oval ; mallei incurved, shorter than the incus, 

 which is also inciu'ved. 



Taphrocampa annulosa. — Occipital 

 mass opaque, white ; alimentary canal 

 simple, wide, cylindrical ; points of tail 

 short, conical. 1-110". 



This species is evidently allied to M. 

 Dujardin's Limlia torulosa, but differs 

 from it in the structm'e of the dental 

 apparatus, and of the digestive canal. 



It seems to connect the genus CTieeto- 

 notus with the Hydatinaean genera No- 

 tommata and Furcularia; for it has the 

 jaws of these larviform Rotifera, and 

 the glandular occipital mass foimd in 

 some of them, with the form, simple 

 digestive canal, and manners of Chceto- 

 notus. Found at Leamington. 



We will append here two genera of the family Furculariens of Dujardin, 

 which that natm^alist has created either to embrace new species or to dispose 

 of those described by Ehrenberg which Dujardin cannot include with other 

 of his genera. Likewise, before commencing with the next family (Euchla- 

 nidota of Ehrenberg), we shaU take the opportunity to detail the characters 

 of a family discovered and named by Dujardin, viz. Albertiens. 



Genus PLAGIOGNATHA (Duj.).— Body oblong, curved and convex on 

 one side, or cornet-shaped and obliquely truncate in front ; terminated pos- 

 teriorly by a more or less distinct tail, bearing two styles. Jaws with parallel 

 branches turned the same way, and recurved towards the ciliated margm with 

 a straight central stem (fulcrum), very long and enlarged at its base ; eye- 

 specks one or two. We propose this as a genus of Furculariens. 



Although possessing a curved figui'e, with a characteristic form of jaws, 

 Ehrenbero- has distributed them in his genera Nofommafa, DigUna, and 



