398 
ORIGINAL ARTICLES. 
Two special fringes of long cilia, separated from one another by 
a deep groove, encircled the whole body, like an elegant scarf. The 
first of these encompassed the anterior ventral buckler crossing the 
ventral surface before the mouth. The second crossed the ventral 
surface behind the mouth, curved backwards on either side of the 
hood, and then passing forwards bordered the dorsal surface in a 
closed circle. The mouth lay in the groove between the fringes, so 
that one closed circle of the ciliated fringe was completely before, 
and the other completely behind it. The anal pore was, of course, 
within the posterior and dorsal fringe. 
Zooids double the size were somewhat more flattened. The an¬ 
terior extremity of the body was prolonged into two fin-like plates, one 
above, the other below, continuations of the dorsal and ventral sur¬ 
faces, and bordered by the ciliated fringes. A little later the borders 
of the dorsal and ventral bucklers were extended, right and left, into 
symmetrical earlike appendages, greatly lengthening their ciliated 
fringe. Muller observed in some of these Helsingfors zooids two 
closed sacs, suspended behind the mouth, and close to the stomach« 
and intestine, with minute spherial granules rotating within them. 
All the pseudembryos seemed to be of the same species. Muller 
regarded them as belonging to a different species of the same genus 
of starfishes, as the form described under the name Bipinnaria 
asterigera. 
9. Professor Muller had, unfortunately, no opportunity of ob¬ 
serving the large Northern species alive, but he dissected and described 
specimens preserved in spirits, and sent to him from Copenhagen, by 
Prof. Steenstrup* and others, of an allied species and of equal size, 
procured on the coast of Sicily, by Dr. Krohn.']' 
In the Northern form, Bipinnctria asterigera of Sars, the anterior 
oral extremity is much lengthened, and has a distinct dorsal and 
ventral sheet of integument, each bordered by a ciliated band, and 
each ending in a flat-lobed fin. The free-lobed extremity of the 
dorsal surface is terminal, that of the ventral surface is placed some¬ 
what further back. The lateral appendages, fourteen in number, are 
crowded in a double line at the posterior, rounded extremity of the 
body. 
In the centre, and within the crown of appendages, a crescentic 
depression, covered by the ventral fold of the dorsal surface-layer as 
. by a hood, contains the pear-shaped mouth. 
As in the young pseudembryo, previously described, the mouth 
passes into a wide muscular oesophagus, which is connected with a 
well-defined stomach, occupying a large portion of the rounded 
posterior extremity of the body, and passing by a narrow constriction 
into a short intestine, which curves backwards and downwards, ending 
in a minute anal pore in the centre of the posterior hood. The 
* Op. cit. 
f “ Ueber die Larven und die Metamorphose der Holothuricn und Asterien.” 
—Berlin, 1850. 
