6 Moll. 
MOLLUSCA. 
but these are in open communication with intestinal lacunae, and water 
can be introduced from without by a cleft in the foot into this system 
of veins and lacunae. In the Oephalopods, there are no lacunae, but only 
sinuses, that is to say, wide expansions of the veins, clothed by their 
proper membrane. Z. wiss. Zool. xxvi. pp. 87-102. 
H. SiMROTH has published an extensive treatise on the organs of sense 
of the Mollusca, chiefly from observations made on the genera. Faludina, 
Neritina, Planorhis, LimncBa^ Helix., Avion, and Cyclas. He describes 
the epithelial cilia and the peculiar terminal corpuscles from different 
parts of the body, the eyes and otolithes, and their nerves, &c., and 
comes finally to the conclusion, that a common sense for mechanical and 
chemical functions, including feeling, smelling, and tasting, is spread 
over the whole surface of the body, but that the sense of smelling is 
more specialized in the feelers, and that of tasting in the front part of 
the buccal cavity of the land-snails, whereas in the aquatic species there 
is no such specialization. Z. wiss. Zool. xxvi. pp. 227-337 and 347, pis. 
xv.-xxi. 
H. V. Ihering has published a treatise on the auditory organs of the 
Mollusca (supra), in which he comes to the conclusion that in most 
divisions the lower forms exhibit numerous small otoconia, the higher 
having large otolithes. 
The auditory organ, acoustic nerve, and otocyst of Pterotrachea are 
fully described by 0. Olaus, Arch. mikr. Anat. xii. (1875) pp. 103-118, 
pi. X. 
The acoustic nerve comes from the supra-pharyngeal ganglion, and not 
from the pedal, in Dentalium ; Lacaze-Duthiers, Arch. Z. exp^r. iii. 
pp. XX. & xxi. 
H. SiMROTii opposes the view of Von Ihering that the pulmonary sac 
of the aquatic Pulmonates or Pulmobranchs is morphologically quite 
different from that of the terrestrial Pulmonata ; he rather regards the 
former as a lower degree of the latter, and discusses the phylogenetic 
origin of the pulmonary sac generally. Z. wiss. Zool. xxvi. pp. 337-347. 
D. Weinland has observed that the copulation of Clausilia hiplicata 
(Mont.) is not simultaneously reciprocal as in other Helicidce : Weich- 
thierf. d. Alb. p. 89. 
The colouring fluid in Murex brandaris (L.) and trunculus (L.), the 
purple of ancient Greeks and Romans, has been the subject of interest- 
ing chemical and spectroscopical experiments by A. & G. Negri, The 
fluid of both species is originally pale yellow, but assumes, on contact 
with atmospheric, air, a violet colour, that of 31. brandaris (L.) only 
under the influence of light, so that it can be called “ photographical,” 
that of 31. trunculus also in darkness. The chemical nature of the 
colouring matter is near that of indigo. The fluid secreted by the 
mantle of several species of Aplysia is first brown, becoming violet in the 
air ; this also has been examined chemically and spectroscopically by the 
authors. The green colour of Elysia viridh (Mont.) and Stiliger souleyeti 
is due to chlorophyll contained in their body. Atti Soc. Rom. (2) iii. 
pp. 394-449, with coloured plates representing spectroscopical views, the 
changes of colour in the fluid of these Mollusks, and the modifications 
