A MONOGRAPH OF THE EXISTING CRINOIDS 6G1 



The remaining 10 specimens are similar to these. 



The example from Siboga station 81 is small, with 16 arms 70 mm. long. 



The type specimen of Alecto parvicirra was without locality. The species was 

 described by Muller from a specimen in the Paris Museum on the basis of notes 

 taken for him by Troschel. As the description published by Muller in 1849 is 

 identical with the original description published in 1841, there is no evidence that 

 Muller reexamined the specimen on his visit to Paris. Dujardin seems not to have 

 found it in the Paris Museum collection, for he said in 1862 that the type was recorded 

 by Muller as in the Paris Museum. Neither Carpenter, who searched twice for it, 

 nor I have been able to find it. The characters as given by Muller are as follows: 



The cirri are XX+, 12, very slender and short. 



The radials are visible. The IIBr series are 4 (3 + 4). The IIIBr series, when 

 developed, are 4 (3 + 4). 



The 27 arms are 82.25 mm. long. 



Syzygies occur between brachials 3 + 4, 10+11, or 11 + 12, and distally at 

 intervals of 3-5 muscular articulations. 



The pinnules are almost uniform. 



The 2 specimens without locality collected by the Gazelle have each apparently 

 20 arms. In 1 of them 8 of the IIBr series are 4 (3 + 4) and 2 are 2, and in the other 

 6 of the IIBr series are 2 are 4 are 4 (3 + 4). In both the centrodorsal is much reduced, 

 with only 1 or 2 rudimentary cirri remaining. 



Regarding the terminal portion of the arms in this species, Dr. Torsten Gisle'n 

 wrote in 1924 that in parvicirra and in Comatula pectinata the anterior arms end as 

 described forAntedon petasus by Mortenseninl920 (see Part 3) the main arm always 

 keeps its character of a main branch and the pinnules arise as small buds alternately 

 to the right and left. On the posterior arms the only difference is that the growth of 

 the main arm is retarded so that the pinnules reach the full size, while the main 

 arm grows not at all, or only slowly. Therefore the arm does not end in an axillary 

 supporting 2 pinnules, but on the last segment that gives rise to a ramification there 

 is an (almost) full grown pinnule and a mam arm composed of a few brachials. As 

 soon as more than 1 or 2 segments have been formed on the main arm a new pinnule 

 develops. The main arm, therefore, keeps its ramified character and never develops 

 as a pinnule. 



Abnormal specimens. In 1 of the specimens from Moreton Bay, Queensland, 1 of 

 the IBr series is 6 (5 + 6). 



In 1 of the specimens collected by Professor Semper at Bohol and described by 

 Carpenter (as Actinometra polymorpha), 1 of the IIIBr series is 1; this bears, next to 

 the median line of the ray, a IVBr 2 series. 



A detached arm fragment from 1 of the 2 specimens without locality collected by 

 the Gazelle exhibits a peculiar case of distal arm division. The pinnule socket of one 

 of the brachials, instead of bearing a pinnule as usual, bears a perfect arm which is 

 slightly smaller than the main trunk and extends outward from the latter in the 

 same plane as the pinnules arising on the same side from the normal brachials. 

 The first and second brachials of this supernumerary arm bear pinnules, and syzygies 

 occur between brachials 3 + 4, 8 + 9, and 13 + 14. 



