ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
771 
Respiratory Globulin in Blood of Chitons.* — Dr. A. B. Griffiths 
has found in the blood of Chitons a respiratory globulin, which has no 
metallic constituent, though possessed of the same power of oxidation 
and reduction as haemoglobin and other bodies. When charged with 
oxygen it is colourless. The author proposes to call it /3-achro[o]globine 
to distinguish it from the achrooglobin of Patella. 
Anatomy and Histology of Proneomenia Sluiteri.f — Herr J. 
Heuscher has a preliminary notice of the results of his observations on 
this archaic Mollusc. In the integument there is a thin hypodermis 
and a greatly developed cuticle. The former consists of a single layer of 
small cubical cells, among which there are groups of eight to ten cells, 
which form small goblet-shaped glands and secrete cutaneous spicules. 
In the cuticle there are, at regular distances from the hypodermis, three 
or four layers of these goblet-glands, all of which are connected with the 
hypodermis by a thin peduncle. As we pass from within outwards we 
find larger calcareous spicules in each layer. In the outer half the 
spicules cease to have any connection with their matrix, but are still 
regularly arranged. Other glands, which Hubrecht did not see, are 
also present in large numbers in the cuticle ; they form a secretion, 
part of which is lost in the cuticle, while part is discharged on the 
surface, and probably cements the detritus which is found firmly 
attached to the animal. Similar glands have been observed in other 
Neomenise. 
The author thinks that the pair of pouches which Hubrecht regarded 
as the byssus, and which are pretty thickly filled with long calcareous 
needles, are, perhaps, organs which have a holding or stimulating 
function during copulation. The cup-shaped depression above the 
cuticle, though agreeing in position with an organ found in other 
Neomenians, differs in structure ; it does not contain either the lamelli- 
form spicules or tactile setae described by Pruvot. The musculature 
of the body-wall recalls that of Annelids, and muscular septa appear to 
divide the body into segments. Hubrecht was inclined to distinguish 
an anterior from a posterior foot-gland on account of differences in 
reaction, but the author finds differences in reaction along the whole, of 
the foot, and believes that they are merely due to variations in secretory 
activity. 
Except in some points of detail, Hubrecht’s account of the nervous 
system is accepted as correct. The dorsal blood series is found to be 
merely a lacuna between the suspensory muscles of the hermaphrodite 
gland ; the ventral sinus is in free connection with the lacunje which 
lie above the “ septum.” Respiration appears to be effected by means 
of the digestive canal ; the papilliform processes which Hubrecht sup- 
posed to be gills are regarded as sensory organs ; the radula is of the 
opisthobranchiate type. The filamentar glands connected with the 
reproductive apparatus, to which no function has yet been assigned, 
except by Pruvot, who regards them as representing a shell-gland, are, 
so far as the terminal portion is concerned, thought to be certainly 
such. 
* Comptes Rendus, cxv. (1892) pp. 474 and 5. 
f Vierteljahrschr. Naturf. Gesell. Zurich, xxxvii. (1892) pp. 148-61 (4 figs.). 
