OPHIURANS OF UNITED STATES NATIONAL MUSEUM. 59 



through the upper braclu'al plates being narrower, and, lastly, through the slight 

 development of the tentacular scale, which is always single beyond the first five or 

 six brachial articles, while it remains double, in A. Inhamula, on two-thirds of the 

 length of the arms. 



I have described recently, under the name of A. Tcukenfhali (13, p. 386), an 

 Amphiura, the under face of the disk of which is covered with fine and regular 

 scaling, extending uninterruptedly until it joins the upper plates, an arrangement 

 very different from the one observed in A.fibulata. In this new species, the brachial 

 spines, which come after the first ventral one, bear at their ends a well-developed 

 distal hook, and sometimes also a little proximal hook, wliich give to some of the 

 specimens a bihamuled appearance, though never so clear as that of A.fibulata or 

 of A. Inhamula; besides, the two tentacular scales are most regularly continued on 

 the longest part of the arms. In short, the two species are altogether different 

 from eacli other. 



I have found in the collections of the United States National Museum a small 

 A. Tcukenihali, which I mention below. 



AMPHIURA KUKENTHALI Kcchlcr. 



Amphiura kukenihali KCEHLER (13), p. 396, pi. 20, figs. 1-4. 



Key West, Florida. One specimen. 



The specimen is of very small size and the diameter of the disk does not exceed 

 4.5 mm., but it entirely agrees with the larger specimens from the West Indies, 

 from which I have just described the species. It was associated with other Ophi- 

 urans: Amphiura abdita, Amphiura stimpsoni, Ophionereis reticulata, and Ophio- 

 stigma isacanthum. 



AMPHIVRA COMPLANATA Ljungman. 



Plate 5, figs. 3-6. 



Amphiura complanata LJUNGMAN (66), p. 319. 

 Amphiura complanata LJUNGMAN (71), p. 642. 



Albatross station 2762. December 30, 1887. Lat. 23 08' S. ; long. 41 34' W. ; 

 59 fathoms; bu. m.; temp. 57.1 F. Several specimens. 



A very short description of tliis species, which, however, is sufficient to recognize 

 it, has been published by Ljungman. I wanted, nevertheless, to compare my 

 specimens with the type which is preserved in the Stockholm Museum, and which 

 has been most obligingly communicated to me by Professor The"el. Ljungman's 

 description being very short, I think it useful to describe the species with a few 

 more details from the specimens gathered by the Albatross. 



The diameter of the disk generally varies from 7 to 8 mm., and it can reach 

 10 and 11 mm. In some examples, the disk of which is 10 mm. wide, the length of 

 the arms is from 75 to 80 mm. 



The disk is flattened, rather thick, strongly excavated in the interradial spaces, 

 and it also shows some sharp notches above the insertion of the arms. The upper 

 face is covered with numerous, small, unequal, and imbricated plates which are 

 smaller at the center and toward the margin in the interradial spaces, and, on the 

 contrary, larger near the radial shields. On the samples of small or middling size, 

 may be seen a rosette of six primary plates ; the centro-dorsal one is rounded and 



