ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
433 
Balanoglossus, for which he proposes the name of Ptychodera austra- 
liensis. Like other species of its genus it is littoral in its habits, and 
occurs in considerable abundance at certain points along the coast of 
New South Wales. The species is especially characterised externally 
by the great development of the genital wings, which completely hide 
the gill area and extend far into the hepatic region, and by the presence 
of two longitudinal epidermal stripes which extend over the anterior 
two-thirds of the tail region, and overlie the two ciliated bands of the 
intestine. In the mode of formation of the proboscis pore this species 
appears to be the most variable of all Enteropneusts which have as yet 
been examined. In most the pore occupies a median position, when it 
may be formed in one of three ways : (1) From the union of both dorsal 
proboscis pockets into a single proboscis canal ; (2) from the left ; or 
(3) from the right pocket alone forming the canal. An interesting 
feature is said to be presented by the ventral wall of the heart-bladder 
which is infolded into the cavity of the bladder, forming a tube free 
anteriorly, and communicating with the central blood space by a narrow 
longitudinal slit. This is regarded as a special modification to ensure 
the better performance of the propelling function of this ventral wall. 
Another interesting point in connection with the vascular system is the 
presence of a well-marked vessel which passes in the “ chondroid ” tissue, 
occupying a space between the anterior portion of the keel of the pro- 
boscis skeleton and the posterior portion of the end plate. 
Echinoderma. 
Comet-form of Linckia multifora.* — Mr. S. Hirota has made a 
study of the comet-shaped form of Linckia , which has from time to 
time attracted the attention of various naturalists. He comes to the 
conclusion that, in a typical comet, the central organs are generally 
developed as in a normal young form with a disc of the same size. The 
younger the comet, the relatively greater in girth are the regenerated 
arms. The stone-canals are formed on both sides of the base of the 
principal arm, and the madreporic plates from ordinary ossicles on the 
dorsal edge of the wound. A local constriction of an arm is not to be 
taken as the preparation for self-breaking, which takes place abruptly, 
but indicates the junction between the original and the regenerated 
parts of an arm. The breaking may be caused in any arm, and at 
various positions, at the will of the animal. This breaking may from 
its frequency be considered as an ordinary mode of reproduction, but it 
does not probably serve any purpose in the fertilisation of generative 
•cells. It is highly probable that the mouth is formed secondarily, but 
not directly from the wound itself. 
Fertilisation of Echinoid Ovum.t — Prof. Th. Boveri has, with the 
practical assistance of Dr. R. Lautenbach, reinvestigated the much- 
studied phenomena of fertilisation in Echinoids. He packed numerous 
ova in the epidermic castings of Cryjotobranchus japonicus, and thus cut 
many at once, staining after Heidenhain’s iron-hmmatoxylin method. Of 
any ovum-centrosome ( ovocentre of Fol) not the least trace was to be 
* Zool. Mag., vii. (1895) pp. 67-76 (1 ph). 
f Verh. Phys. Med. Gesellsch. Wurzburg, xxix. (1895) pp. 1-75. 
