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margin of the head is sinuate, and the front margin is boldly rounded. The last thoracic segment 



is contracted posteriorly. The apex of the segment is narrowly rounded, then slightly sinuate as it 



merges into the dorsal line. The rostrum is composed of two long and moderately stout filaments 



attached to a projection of the forehead. Each filament is distinctly bifurcate at the apex. 



Ihe abdomen is composed of four segments. The combined length of the abdomen and 



furca is contained four times in the total length of the ccphalothorax, from the frontal margin 



to the base of the genital segment. The genital segment is as long as the combined length 



of the second and third segments. The anterior portion of the ventral surface is only slightly 



produced. The second and third segments are of about equal length. The fourth segment is 



very small and is distinctly less than one-half of the length of the third segment. The furcal 



joints are about as long as broad, and are slightly longer than the anal segment. 



The antennules are twenty-four-jointed and extend slightly beyond the furca. 



The antennae, mandibles, maxillae and maxillipedes are similar to those of Scolecithricella 

 tydemani. 



The first pair of feet is also similar to that of the above species. 



The exopodite of the second pair of feet is distinctly narrower than in Scolecithricella 

 tydemani. The surface of the second and third joints is well clothed with fine spines. The 

 second joint of the endopodite is furnished with three transverse rows of fine spines. 



The exopodite and endopodite of the third pair of feet are almost similar in armature 

 to that of Scolecithricella tydemani. 



The exopodite and endopodite of the fourth pair of feet are three-jointed. The joints are 

 comparatively narrow and the surface is closely set with small points (Plate XXX, fig. 8). 



The fifth pair of feet is represented by two free joints attached to a basal part. The 

 joints are comparatively narrow and the second joint is fully twice the length of the first. The 

 second joint is furnished with one strong spine near the distal end of the inner margin. The 

 spine is as long as the joint, and its outer surface is fringed with fine spinules. The apex of 

 the joint is much contracted and bears one short, stout, naked spine. The apical spine is equal 

 to about one-fifth of the length of the inner-edge spine. The outer margin of the joint is plain. 



The male is unknown. 



This species is readily separated from the other members of the genus by its long body 

 and short abdomen, and by the structure and armature of the fifth pair of feet. 



Occurrence. — Two specimens were obtained from the plankton collected with the 

 Hensen vertical net at Station 148, 1000 metres to the surface. 



Genus Scaphocalanus G. O. Sars, 1900. 



Sars established this genus in 1 900 for a Calanoid found in the plankton collected during 

 Nansen's Xorth Polar expedition, but was then unaware that it had previously been described 

 by my father and placed in the genus Amallophora (1893), as well as by Giesbrecht in 

 ! ^95i wno placed it in the genus Scolecithrix. The genus Amallophora was disestablished by 

 Giesbrecht and Schmeil in 1898. These authors placed Amallophora typica in the genus 

 Xanthocalamis. The other species described by my father were included in Scolecithrix. 



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