1^ CALAMOCEIHUS DIOMEDjE. 



there were syzygial joints on the second joint between the first and second 

 axillaries, on the second and third joints between the second and third 

 axillaries, and on the first, third, fourth, and sixth, between the third and 

 fourth axillaries. 



In the arm figured on Plate I. Fig. 1 (the right arm) there are syzygies 

 on the second and fourth joints between the first and second axillaries; on 

 the second, fourth, and fifth joints between the second and third axillaries; 

 and on the first, third, fourth, sixth, and seventh joints between the third 

 and fourth axillaries. 



On the left arm of the same Plate, the first, third, fourth, and fifth joints 

 were syzygial joints between the first and second axillaries: the same was 

 the case with the second, fourth, and fifth joints between the second and 

 third axillaries; while the second, fourth, fifth, and sixth were Byzygial 

 joints between the third and fourth axillaries. Between the fourth and 

 fifth axillaries. the first, second, third, fifth, sixth, and seventh joints had 

 syzygial joints. 



In the case of the branches, many single joints separate the syzygies; 

 in one branch six and sixteen pinnule-bearing joints intervened between 

 the syzygies. and in another four and eighteen. 



As far as the position of the pinnules is concerned, the first pinnule 

 of the anterior arm is on the left of the third brachial (Plate III. Fig. 1) ; 

 the second is on the right on the epizygial of the fourth ; the third on 

 the left again on the epizygial of the fifth brachial j and the fourth on 

 the right on the sixth joint in the same specimen. We find the same 

 arrangement in the order of the pinnules of the other arms in this specimen 

 (Plate III. Fig. 1), while in the specimen on Figure 2 of Plate III. the third 

 pinnule is on the fifth brachial ; see also Plate V. Fig. 1. On the left 

 posterior arm the first pinnule is on the third brachial, the second on the 

 epizygial of the fourth, the third on that of the fifth, and the fourth pin- 

 nule on the sixth brachial, there being four pinnules below the first axillary 

 (Plate II. Fig. 2, Plate V. Fig. 2). This is also the case in other arms, in 

 which there are seven brachials below the first axillary; even when we 

 have only six brachials, there are five pinnules in one case below the 

 axillary (Plate V. Fig. 4). 



The first brachials are much wider than the succeeding ones (Plate III. 

 Figs. 1.2). and the brachials taper gradually towards the first axillary. The 

 lower brachials are somewhat compressed vertically, while both the main 



