STRUCTURE AND DEVELOPMENT OF LOXOSOMA. 
263 
individuals observed possessed more than a single bud, which 
was provided with a foot-gland, a structure absent in the adult. 
The larva (see Barrois' figure, No. 13) is not unlike that of 
L. neapolitanum (Kowalewskv, No. 3, fig. 10). 
(There can be little doubt that the species just described is 
identical with L. claviforme, Hincks (26), occurring on 
Hermione hvstrix. Hincks acknowledges that his dia- 
gnosis is very incomplete, owing to the bad preservation of his 
material, and it has seemed to me better, therefore, to identify 
my species provisionally as L. singulare, until the distinctness 
of L. claviforme can be more satisfactorily shown.) 
4. L. crassicauda, Salensky, found in large numbers 
attached to the floor of a tank in the Zoological Station. The 
number of buds is large, two, three or more occurring in most 
cases on each side of the body. The number of tentacles is typi- 
cally eighteen, but is by no means constant (fig. 1 ; — seventeen 
tentacles). The individuals are much larger than those of any 
other species discovered ; the stalk is very long, with no regular 
arrangement of its ectoderm cells, the foot-gland being absent 
or (Schmidt) preserved as a rudiment in the adult ; the termi- 
nation of the stalk is cylindrical. Numerous gland-cells occur 
at the edge of the calyx, whilst the special development of two 
posterior sense organs (fig. 1, jos.) is a noteworthy feature of the 
species. The larva is at present unknown. 
5. L. Leptoclini, Harmer, new species, not uncommon 
at Naples on the compound Ascidian Leptoclinum macu- 
losum. I propose for the new form the specific name 
Leptoclini ; as far as my observations extend, it is confined 
in its occurrence to the genus Leptoclinum, although I 
have searched for it on numerous genera of Sponges and 
Ascidians. The number of tentacles is perhaps invariably ten 
in the adult ; the buds are few, although the occurrence of three 
at the same time, as in L. Tethyse, is by no means rare. The 
individuals are small, their total length (with the stalk) 
averaging about half a millimetre (the measurements having 
been made from glycerine preparations). The stalk is at most 
about equal in length to the calyx, which has the character- 
VOL. XXV. NEW SER. 
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