. Discovery reports. Discovery (Ship); Scientific expeditions; Ocean; Antarctica; Falkland Islands. THE APPENDAGES, THEIR INTERRELATION AND FUNCTION 3°7 (Fig. 4, ) extends into the oral atrium. As mentioned above, it forms a lateral boundary to the atrium (Figs. 7 and 8). Anteriorly at this lower end the coxa is produced into a distally directed process (Fig. 4 B, ), which Skogsberg (1920, p. 570) describes as more or less triangular and 'against which the endite on the following joint rests with an antero-inner edge'. Skogsberg also refers to the term 'Zahnhocker' adopted by Claus (189
. Discovery reports. Discovery (Ship); Scientific expeditions; Ocean; Antarctica; Falkland Islands. THE APPENDAGES, THEIR INTERRELATION AND FUNCTION 3°7 (Fig. 4, ) extends into the oral atrium. As mentioned above, it forms a lateral boundary to the atrium (Figs. 7 and 8). Anteriorly at this lower end the coxa is produced into a distally directed process (Fig. 4 B, ), which Skogsberg (1920, p. 570) describes as more or less triangular and 'against which the endite on the following joint rests with an antero-inner edge'. Skogsberg also refers to the term 'Zahnhocker' adopted by Claus (1891) for this process. In fact the structure is much more rounded than is suggested by these descriptions and is directed (it should be noted) much more nearly parallel to the longitudinal axis of the coxa than is shown in the figures given by Claus (1891, pi. xxn, figs. 6 and 15). The statement that the endite of the following joint rests on it is quite erroneous. No doubt Skogsberg based it upon observations of isolated mandibles. Examination of the appendage in situ and in section, shows that the process fits exactly into a thickened socket, which is part of the. Fig. 6. C. borealis antipoda. Diagrammatic anterior view of a thick transverse section through mandibular region. (Antennal shafts omitted to show mandibular coxae.) a^, base of antennules and frontal organ; a2, antennal socket; , dorsal articular condyle of mandibular coxa; , distal articular process of mandibular coxa; fl, anterior dorsal flange of mandi- bular coxa; ist, isthmus linking body with carapace; lb, labrum; , mandibular basis; , mandibular coxa. sclerite framework supporting the oral surface of the labrum (Fig. 4 A, and , Fig. 8). The projection of this peg into the socket in the labrum is sufficiently deep to make it difficult to remove the appendage during dissection. The mandibular coxa is thus restricted in its movement to rotation about the axis formed by this articular pro
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