ACriNOMETU \ I'ARVICIÜRA. 



^07 



imens have shown that there is a pigmented cellular cord 

 beneath the watervessel , and lateral trunks connecting 

 the subtentacular and coeliac canals just as in the Phil- 

 ippine examples ^) , while the histological features of the 

 ovary are identical in both. The Timor specimens also 

 have several arms which are ungrooved either for the whole 

 or for the greater part of their length. The proportions 

 of ungrooved arms in the three individuals are respectiv- 

 ely To > i^ and If. The grooved anterior arms taper 

 slowly, having 120 -)- joints, while in the short hinder 

 arms there are only about 70 joints the last half of which 

 lose the wedgeshaped appearance presented by the lower 

 joints and become rapidly blunter and squarer ; but they 

 never become elongated like the terminal joints of the an- 

 terior arms. 



Another specimen referable to this species is one from 

 Bennett's collection, from some unknown locality in the 

 East Indies. The overlap of the arm-joints is nearly as 

 marked as in the Timor examples, but the spines on the 

 outer cirrhus-joints are less developed and fewer of the 

 lower pinnules have a terminal comb. This individual is 

 remarkable for having dimorphic arms which are all groov- 

 ed. The posterior arms taper much more rapidly than 

 the anterior ones and are composed of fewer joints , but 

 their ambulacra are nearly as well developed. 



Two other examples of the same type were obtained at 

 the Island Solor by Dr. Semmelink. They both agree in 

 the relatively small size of the pinnule on the fourth brach- 

 ial, and in having the terminal, comb on the lowest pinn- 

 ules larger than in the Timor specimens though the 

 number of pinnules bearing it is small, not more than five 

 or six on each arm. The overlap of the arm-joints also 

 is less marked. While resembling one another iu their 

 differences from the type, these two individuals from So- 

 lor are nevertheless very unlike. 



1) Journ. Anat. and Physiol. X. 1876, pp. 5S1, .582; XI, 1877, pp. 90,91. 

 >3"otes from the ILieydeii TMiiseum, Vol. III. 



