244 
THE CEPHALOPHORA. 
§ 215. 
§ 215. 
With those Cephalophora which are nourished by solid food, and which 
often have, therefore, masticatory organs, there are, almost without exception, 
highly-developed Salivary organs. 
These are usually composed of two lob- 
ular yellow glands surrounding the cesophagus or stomach, and which have 
in front two excretory ducts which are lined with ciliated epithelium.“ 
These ducts pass, in company with the cesophagus, through the cesopha- 
geal ring, and, extending over the base of the pharynx, end in the oral 
cavity on each side of the tongue. 
sist of two very long tubes. 
organs, one of which opens at the anterior part of the mouth, 
With some species, these glands con- 
Some Gasteropoda have two pairs of these 
In a few 
cases only these organs appear to be wholly wanting.” 
The Biliary organs are always present ; and their glandular follicles con- 
tain hepatic cells filled with a brownish-yellow substance. 
Most com- 
monly, the liver is large and distinctly separated from the digestive canal ; 
and it is with a few genera only that it is more or less blended with it. 
1. This last is the case with some Pteropoda, and Apneusta, whose 
intestinal walls, as with the Worms, are partly composed of the hepatic 
substance, or furnished with numerous small follicles which open into the 
intestinal cavity.© 
1 Helix, Limax, Onchidium, Haliotis, Pleu- 
robranchus, and the Pectinibranchia. For the 
internal structure of these glands, see Miller, De 
Gland. secern. struct. p. 54, Tab. XVII.* 
2 Clio, Aplysia, Thetis, Lissosoma, Tergi- 
pes, and many species of Doris. 
3 Janthina, Flabellina, Actaeon, and Atlanta. 
With sume Guasteropoda, as for instance, with 
Rhodope, and Eolidina, there are only two sali- 
vary glands; these open in front into the oral 
cavity and so far from the cesophagus that they 
appear to correspond to the anterior pair of those 
species in which there are four. f 
4 Sagitta, Cymbulia, Tiedemannia, Denta- 
lium, and Chiton. 
5 For the internal structure of the liver of the 
Gasteropoda, see Muller, De Gland. secern. &c. 
p. 71, Tab. X. ; Schiemm, De hepate ac bile Crus- 
tac. et Mollusc. quorundam, loc. cit. p. 19, Tab. I. 
II. ; Karsten, Nov. Act. Acad. Nat. Cur. XXI. 
p. 304, Tab. XXI.; and H. Meckel, Miiller’s 
Arch. 1846, p. 9, Tab. I. 
6 With Sagitta, the hepatic substance appears 
* [§ 215, note 1.] See also Leidy (loc. cit.) for 
the salivary glands and their intimate structure, of 
Limaz, Helix, Tebennophorus, Vaginula, Suc- 
cinea, Glandina. 
t [§ 215, note 3.] With Paludina, the salivary 
glands are highly developed and two in number. 
They are situated on the upper and posterior side 
of the pharynx, behind the brain ; their excretory 
ducts pass under the cerebral commissure, for- 
wards, and perforate the upper wall of the pharynx. 
In structure they consist of ramose caeca, made 
up essentially of cylindrical epithelium situated on 
a basement membrane ; see Leydig, loc. cit. p. 
165, Taf. XII. fig. 10, a. b. 
For further details on these organs with the 
Nudibranchiate Cephalophora in general, see 
to be blended with the intestinal walls (Krohn, loc. 
cit. p. 8). This is distinctly so with Venilia, Aeolis,, 
Eolidina, Amphorina, and Zephyrina, and is- 
especially seen upon the coecal ends of the 
branches of the intestinal canal which terminate 
partly in the dorsal appendages, and partly in the 
parenchyma of the body ; see Quatrefages, loc. cit. 
XIX. p. 289, Pl. XI. fig. 5, I. Pl. IV. V. 3 Adder, 
Hancock and Embleton, Ann. of Nat. Hist. XIII. 
p- 163, Pl. II. fig. 9, XV. p. 80, PI. IV. According to. 
Nordmann (loc. cit. p. 20, Tab. II. III. fig. 3), the 
liver is isolated with Tergipes ; but as the organ. 
here described appears to open externally by a 
special duct, it resembles an urinary organ (see 
below, § 223). With Pnewmodermon, and Clio, 
the stomach is lined with a layer of small hepatic 
follicles (Cuvier, loc. cit. p. 8, fig. 7, p.; and 
Eschricht, loc. cit. p. 11). 
According to a communication from Kédliker, 
the intestine of Rhodope also has numerous folli- 
cles of this kind, which are pyriform and filled 
with cells having yellow nuclei. 
Alder and Hancock, loc. cit. Part If. Pl. IV. fig. 
1, f. (oto) ; Part III. Pl. VII. fig: 6, a. (Aeolts) 5 
Part IV. Pl. V. fig. 1, c. (Scyllaea) ; Part V. Pl. 
II. fig. 1, h. (Doris). — Ep. 
t [§ 215, note 5.] See also Leydig, Ueber Palu- 
dina vivipara, &c., loc. cit. p. 143, 166 (Paludi-~ 
nda) ; he gives its development and its adult struc-- 
ture. It is developed from cells as an appendage 
to the alimentary canal; and its structure, when. 
complete, is follicular, as above described. See 
furthermore, for the liver of the terrestrial Gaster- 
opoda, Letdy, loc. cit. Of its internal structure, 
he says: ‘The lobuli of the liver are composed of 
the rounded commencement of the biliary ducts, 
and are lined with polygonal cells.” — Ep. 
