670 SYSTEMATIC HISTOET OF THE INFUSORIA. 



fission ; at c the ovum has undergone several repetitions of the yelk- division ; 

 and at d is an ovum in which the contour of the embryo is visible. The two 

 eye-spots seen at d ; and the so-called dark urinary concretion, seen also in 

 embryonic Melicertce and others, at Jc. The real nature of this last object, 

 which is seen only in the embryonic state of these animals, is yet doubtful. 

 Fig. 3 represents a very young Ste^hanoceros a little after its liberation 

 from the ovum ; and fig. 4 another immediately after its liberation from its 

 shell. The dorsal aspect of the jaws of the maxillary bulb, according to 

 Mr. Gosse, is represented in XL. 27, and the obhque aspect of the incus in 

 XL. 28. 



Genus LIMMAS (XXXII. 388-392; XXXYI. 2). — Eyes two; case 

 (ui'ceolus) solitary ; rotary organ two-lobed when fully grown, being then 

 constricted in the middle ; alimentaiy canal simple, terminating at the base 

 of the foot or tail ; stomach, two jaws mth teeth, and two glands also 

 present. The ova are deposited within the case, where they are developed ; 

 neither male organs nor water- vascular canals discovered ; two visual organs 

 indicate sensation: these in the young animalcules are red, and are even 

 visible within the ovum ; but in old age the colour disappears, and hence 

 they are not seen. In the middle of the rotary organ, when expanded, are 

 seen foiu' large globules, which Ehrenberg erroneously considers nervous 

 ganglia, or brain. 



LiMNiAS Ceratophylli (xxxii. 388-392 ; 

 XXXVI. 2). — Case white at first, after- 

 wards brown or blackish; smooth, but, 

 being viscid, often covered with extra- 

 neous particles ; its connexion with the 

 animalcule is a voluntary act of _ the 

 latter; the two red eyes and the jaws 

 may be observed in the ova when de- 

 veloped; by giving the latter a gentle 

 pressm-e the sheU bursts, xxxn. 389 

 exhibits an animalcule just emerged from 

 the e^^, 392 ; 391 a young specimen, 

 with a rotary organ nearly circular, and 

 two eyes ; 390 a full-grown specimen, 

 without its case, fed on indigo — the 



jaws (each of which has three strong 

 teeth), the ova, and the traces of lon- 

 gitudinal muscles are seen, the wheel 

 is folded up ; 388 another, within its 

 case, having the lobed rotary organ ex- 

 panded, (xxx^i. 2. is more magnified.) 

 Found upon hornwort (Ceraiophyllum) 

 and other aquatic plants. Length about 

 1-20"; case 1-40". 



L. annulatus (Bailey). — The case is 

 ribbed and semitransparent, and is com- 

 posed of a linear series of rings. Found 

 in a ditch at Witlingham, near Norwich, 

 on duck weed (Brightwell) ; and by Dr. 

 Bailey near New York, U.S. 



Genus CEPHALOSIPHON. — Eotary organ bilobed ; eyes two ; sheath 

 single ; two frontal horns, including the siphon. 



Cephalosiphon Limnias. — Sheath membranous, annulate. 1-6"' to 1-5"'. On 

 Ceratophyllum. Berlin, Jul3^ 



Genus LACINULARIA (XXXVII. 19-25). — Eyes two (in the young 

 state) ; the cases (urceoli) conglomerate, or growm together ; rotary organ 

 two-lobed when fuU-grown, but nearly circular when young : this organ is 

 the chief instrument of locomotion. Band-like longitudinal muscles exist 

 within the body. Pharyngeal bulb large, with two jaws, and teeth in rows ; 

 oesophagus short, narrow ; stomach elongated, transversely constricted, and 

 with cEecal (?) appendages ; short. The ovarium is situate about the middle 

 of the body, and opens, along with the intestine and the contractile sac of 

 the water- vascular canals, into the caecum. Visual organs exist in the young 

 state ; red in the developed ovum, but becoming darker as they advance to 

 maturity. Globular bodies support the oesophagus on each side ; and below 

 the mouth is a small organ, supposed to be the brain. 



