CALAMOCRINUS DIOMED.E. 17 



tlie two interradials of Apiocrinus insigiiis. (See de Loriol, Plate 56, 

 Fi*'. 2^) The second radial in Hyocrimis is not wide, but narrow, as in 

 Calamocrinus, a feature which, according to Carpenter, is also cliaiac- 

 teristic of Millericriniis Milleri, and a few other species. 



The cal3'x, though symmetrical in all Neocrinoids, may undergo distor- 

 tion (Eugeniacrinidiv, Holopidix?). In Thaumatocrinus and in Calamocrinus, 

 thouo-h to a less extent, the anal radials are larger than the others.* 



The Arms. 



Calamocrinus has five arms (Plate II. Figs. 1, 2, Plate III. Figs. 1-3, Plate 

 VI. FW. 1), and, as far as we can judge from the fragments of the arms which 

 could be reconstructed, there are three forks to the right and two to the 

 left in one case (Plate I. Fig. 1), but in the adjoining arms of the same figure 

 there were evidently three branches on the left and two on the right. 

 Jud "-ing from the specimen figured in Plates II. and III., the first branch of 

 the anterior arm was to the left (facing it). The same was the case with the 

 left anterior and the left posterior, while in the right anterior arm the first 

 branch was to the right. In the anterior and left posterior arms the first 

 axillary was the seventh brachial joint (Plate III. Fig. 2) ; the same was the 

 case in the right and left anterior arms. In another specimen the axillary 

 of the same arm was the eighth brachial, there being three syzygies in 

 this arm, in the first, fourth, and sixth brachials, while in the former case 

 there were three syzygies, in the first, fourth, and fifth brachials. We find 

 the same difference in Plate I. Fig-. 1, and in Plate IV. Fig. 1. The second 

 axillary (Plate II. Fig. 1) is the (twelfth brachial) fifth joint from the first 

 axillary in both the anterior and the right anterior arms, while in Plate 

 IV. Fi"-. 1, it is the sixth joint in that arm. The third axillary is airain the 

 sixth joint from the second, while the fourth axillary is the eighth joint 

 from the third axillary. In Plate II. Fig. 1, the second, third, and fourth 

 axillaries are on the same joints as those of the arm of Plate IV. Fig. 1, 

 while the fifth axillary is the eleventh joint from the fourth axillary. In 

 the right arm of Figure 1, Plate I., the arrangement of the axillaries is the 

 same, but the fourth axillary is the ninth joint from the third axillary, and 



not the eighth. 



In the arms in which there are seven joints to the first axillary there 

 were syzygial joints on the first, fourth, and sixth joints. In the same arms 



* See also Carpenter and Etheridge, Ann. JIag., 1S71, p. 285, Allagecrinus. 



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