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SIDNEY F. HAltMER. 
the oval indented, thus indicating the hippocrepian form of 
the lophophore in other species. Number of tentacles very 
small, about twenty-two. Metasome (body) sharply divided 
into two distinct regions, the distal portion with strong longi- 
tudinal bundles of muscles, the proximal portion with an 
extremely thin body-wall in which muscles are absent or at 
most very slightly developed. The proximal end of the 
muscular region is slightly invaginable, so that in contracted 
specimens this portion forms a shallow cup surrounding the 
more distal part of the muscular region. About fourteen 
bundles of longitudinal muscles occur on each side in the 
distal portion of the body. Regeneration of the lophophore 
occurs with great facility, and this regeneration is frequently 
the result of transverse fission. 
Phoronis oval is differs from other species in its rela- 
tively minute size, in the remarkably simple character of its 
lophophore, which is, however, hippocrepiform, in the very 
small number of its tentacles, and in the sharp differentiation 
of its body into two regions, the proximal end of the muscular 
region being slightly invaginable. As the occurrence of 
functional gonads in some of the specimens indicates that it 
is really an adult form, the claims of the species here 
described to be regarded as a distinct species seem to be 
incontrovertible. 
P. oval is has often been referred to in literature, but as 
no subsequent observer has hitherto succeeded in obtaining 
it, these references are all based on Strethill Wright’s original 
account. De Selys-Longchamps (1903, p. 32) has stated that 
he considers the claims of P. ovalis to specific rank not 
improbable, and that Actinotrocha pallida, Schneider, 
may be its larva. 
The only description which might refer to the same species 
is Van Beneden’s account of C rep in a gracilis (1858 1 , 
1858 2 ). This was described as having from twenty -four to 
forty tentacles, and as reaching a length of 8-10 mm. The 
epidermis is provided with numerous stiff hairs, the points of 
which project to the exterior. The lophophore, as shown in 
