ATLANTIC AND CARIBBEAN PYCNOGONIDA—HEDGPETH 267 
third and fourth joints of the palpus is not evident except as a con- 
striction in the Brazilian variety. In the sargassum specimens from 
Texas the segmentation between these joints is more plainly marked 
but does not seem to be a functional articulation. These specimens 
are all quite small, being not more than 4 mm. in extent, and usually 
about 3 mm. (fig. 8). 
Both Norman (1908) and Bouvier (1923) considered Clotenia 
conirostris Dohrn (1881) synonymous with 7’. orbiculare. Except for 
the 4-jointed palpi, which Marcus considers a character of generic 
importance, C. conirostris 1s very similar to JT. orbiculare, and the 
occurrence of the Brazilian variety suggests that we have here a 
somewhat complex species and that the genus Clotenia is untenable. 
Ficure 49.—a, Tanystylum orbiculare Wilson; b-d, T. calictrostre Schimkewitsch; b, Dorsal 
view; c, tarsus and propodus; d, palpus. 
Perhaps the European and Brazilian forms are geographical varieties 
of T. orbiculare. In the Brazilian form, however, the segmentation of 
the third and fourth joints of the palpi is indistinct but not completely 
obliterated, whereas in the European C. conirostris the palpi have lost 
yet another joint. None of the published figures indicate this char- 
acter very clearly, and without comparative material from Europe it 
seems best to consider C. conirostris at least specifically distinct from 
T. orbiculare. Unfortunately none of the Texas material seems to be 
sexually mature, but it is not improbable that mature specimens will 
show transitional relationships between the North and South American 
varieties. 
