OF THE TRVCHELINA. 



625 



vestigation by Stein. The circlet of teeth 

 (bacillar apparatus, Lachmanii) is con- I 

 structed of no actually separate portions ! 

 or teeth, as Ehrenberg supposed, but is \ 

 nothing more than a tliickened cesopha- ' 

 gus with denser rug?e, or folds, of a chi- [ 

 tinous composition. From its lower end | 

 a digestive tube extends to nearly the ! 

 centre of the body. | 



C. tnicinatus. — Depressed, oblong, 

 rounded at the ends. The right side of 

 the anterior part is produced, so as to 

 appear like a hook or beak. In vegetable 

 infusions. 1-430". 



This being is, in Stein's opinion, a 

 mere variety of C. Cuculhdus : the bulging I 

 out of the side has a somewhat hook-like 

 process ; but this is a mere accidental re- 

 sult follo's\'ing the process of longitudinal 

 self-division {Infus. p. 130). It has been 

 seen to encyst itself. 



C aureus. — Ovate-conical, tm'gid, of 

 a golden yellow colour ; dilated and ob- 

 tusely rostrated anteriorly, attenuated 

 posteriorly. 1-140". 



C. oniatus. — Ovate subcylindrical, of 

 a golden yellow coloiu", equally rounded 

 at both ends, slightly beaked j it has a 

 bright violet spot. 1-180". 



The violet spot spoken of has no di- 

 stinctive peculiarity ; it is not a normal 

 coloured gastric fluid, but only a collec- 

 tion of granides, the same as in Kassula 

 elef/ans. '. 



This species, together \\dth the fore- i 

 going C. aureus and the Nassula aurea, \ 

 are so very similar, that Stein doubts '• 

 their independent natm'e, and is more dis- \ 

 posed to regard them as developmental 

 phases of the same being*. 



C. depressus (Perty). — Irregular, with- 

 out a beak, and roimded at both ends ; 

 compressed; almost colomless. Trans- 

 parent, with greyish contents. Upper and , 

 under surfaces equally flat. Tooth-cylin- i 

 der very evident. Sv^atzerland. 1-120". j 



Stein states that the body is bilateral, 

 presenting a distinct right and left side, 

 an upper (dorsal) convex and a lower 

 (ventral) flat surface. The anterior end 

 is much flattened and transparent; and 

 being curved towards the left side, gives 

 the whole being a somewhat reniform 

 flgm-e. The depression on this side is 

 always in advance of the middle of the 

 body, just as in Paramecium Colpoda and 

 Colpoda CucuUulus. The anterior, curved 

 transparent end suimounts the body like 

 a crescentic process, is fm-nished with 

 longer cilia than elsewhere, and may not 

 inaptly be called the lip. Yibratile cilia 

 cover the body in regular rows, but in 

 very young specimens are invisible ex- 

 cept on the lip. The oval nucleus is 

 hollowed by a cavity, within which is a 

 nucleolus. Longitudinal and transverse 

 fission takes place in individuals of all 

 sizes. The former advances from the 

 posterior extremity ; the oesophageal 

 (dental) cylinder is not divided, but is 

 produced de novo in the newly produced 

 segment: this segment, when first de- 

 tached, is the CJiilodoii uncimdus (Ehr.). 

 CJulodon Cuculhdus encysts itself : a soft 

 gelatinous matter is first thrown out 

 around it, which hardens into the cyst- 

 wall ; during this process the superficial 

 cilia and the oesophageal cylinder disap- 

 pear, and at length an oval cyst, with a 

 large nucleus, and two to three contractile 

 spaces alone appear. Gradually a cili" 

 ated embrj'O is developed from the 

 nucleus, resembling in external charac- 

 ters a Cyclidiu7n Glaucoma. The embryo 

 escapes from the parent animal ; and 

 cysts are sometimes found containing 

 tiie parent and its oflspriug side by side 

 within it. The development of embryos 

 may go on until the nucleus is expended. 

 The size of the germ is determined by 

 that of its parent. 



Genus NASSULA (XXIV. 310, 311 ; XXVIII. 2, 3, 11-15). — Covered 

 with cilia ; ovoid or oblong ; turgid and prominent in front, bnt without the 

 expansion or beak on one side ; month lateral, pro\dded with a cii^clet of teeth, 

 m the form of a wheel {nassa). Xumerons vacuoles are seen, and in two 

 species, as Ehrenberg states, the discharging orifice. The violet-colom-ed 

 granular spots noticed in Chiloclon oniatus occur also in the species oi JS^assula, 

 and are likewise met T\dth in Bursaria vernalis, TracheVms Meleagris, Amphi- 

 leptus margaritifer, A. Meleagris, and A. longicollis. " They resemble," says 

 Ehrenberg, " the vesicular glands around the stomachs of the Rotatoria, and 

 are probably of a glandular nature, analogous to biliary glands, and concerned 

 in the process of digestion." The nuelens is large, oval or spherical ; and there 

 are one or more contractile vesicles. Only transverse self-division has been 



