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SARs in 1902 recognised the identity of Scolecethrix (Amallophora) magna (T. Scott) 
with his Scaphocalanus acrocephalus, and revived the generic name of Amallophora for magna, 
and two other species that were originally established in the genus. Sars left the type species, 
Amallophora typica, in the genus Xanthocalanus. FARRAN (1908) points out that this revival 
cannot be upheld as Amallophora magna is not congeneric with Amallophora typica, with which 
I quite agree. The sensory appendages at the apex of the first pair of maxillipedes of Amallo- 
phora magna and Amallophora typica are quite distinct, and very important differences exist 
between the structure of the fifth pair of feet of the two sexes of both species. I agree with 
Sars, however, that the differences between Amallophora magna, and typical Scolecethrix or 
Scolecithricella, are worthy of generic distinction. I have already employed the name Amallophora, 
for the separation of the type species from the genus Xanthocalanus, and another generic 
name is necessarily required. I have, therefore, revived Sars’ generic name Scaphocalanus for 
Scolecithrix (Amallophora) magna, and the other allied species. The following are the characters 
by which the genus can be distinguished from the other members of the family. 
The female, in general appearance, resembles the females of the genus Scolecithricella, 
except, that it is less robust and rather more attenuated. A median crest may be present or 
absent on the forehead. The rostrum consists of two, very long, simple filaments. The filaments 
are slender and are gradually attenuated to a fine point at the apex. The antennules are 
composed of twenty-three joints. The endopodite and exopodite of the antennae are of about 
equal length. The apical portion of the first maxillipedes is similar to that of Scolecethricella. Two 
types of sensory organs are present. Some are moderately long and simple, others are short, 
with distinctiy swollen heads. The four pairs of swimming feet are similar to those of Scodect- 
thricella, but the spines on the surface of the joints’are stronger and more irregularly placed. 
The terminal spine on the exopodite of the second, third and fourth pairs of feet is more’ 
coarsely toothed than in Scolecethricella. The fifth pair of feet is represented by one or two free 
joints attached to a basal part. The inner marginal spine, and the apical spine on the last 
free joint is of considerable length. 
The male resembles the female in appearance, but there is no trace of a crest in the 
males of those females that possess one. The mouth organs are considerably reduced. The 
fifth pair of feet forms a well developed prehensile organ. Each foot consists of a two-jointed 
basiopodite, an exopodite and an endopodite. The second joint of the basiopodite of the right 
foot is greatly swollen in its proximal part, where it bears a styliform endopodite. The distal end 
of the joint is much attenuated, and the apex is produced on the inside, into a short blunt process. 
The endopodite is two-jointed, short, and slightly curved. The second joint is usually lamelliform. 
The two-jointed basiopodite of the left foot is long and cylindrical. The endopodite and exopodite 
are three-jointed and subequal. The endopodite is usually a little longer than the exopodite. 
The long slender filamentary rami of the rostrum, the long spines on the apical joint 
of the female fifth pair, and the structure of the male fifth pair of feet, easily separate this 
genus from any of the other known members of the family. 
Three species were represented in the plankton collected by the ‘Siboga’, one of which 
appears to be new. 
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