16 AMPHIUEA SQUAMATA. 



out conspicuous primary plates; usually about four scales in the length of a 

 mm., and even fewer on the under surface. Radial shields small, irregular 

 oval, slightly diverging, separated by a wedge of four scales in a line and one 

 or two smaller ones on the sides; length to breadth, 1 : .5. Arm-spines, near 

 disk, six, rounded, tapering, sharp, increasing in length from the upper to the 

 imder one, whose lengths to that of an under arm-plate are .7, .9 : .5. Ten- 

 tacle-scales two, minute, and standing at right angles. Tentacles, especially 

 those of the mouth, thick and cross-wrinkled. 



Color, in alcohol, nearly white. 



In young specimens the lower disk-scales are feeble. 



Hassler Expedition ; Juan Fernandez, 220 fathoms. 



I have been of the opinion that Ljvmgman's genus AmjMpholis was not suf- 

 ficiently grounded, diftering fi'om Amphmra only in having three or four 

 mouth-papilltB on a side, instead of two with a space between them. The 

 present species comes in as a connecting form ; and a glance at Plate V. will 

 show that the variety in number, shape, and position of mouth-papillie in the 

 genus Amphiura, including AmphiphoUs, is considerable. 



Amphiura squamata Sars. 



I am not able to distinguish a specimen from Chili from the A. squamata of 

 South and North Europe, or of North America. Already {Bull. Mus. C. Z., 

 III. 335) I have called attention to the possible identity of species nearly 

 allied to this and coming from distant localities. Ljungman endeavors to 

 distinguish these species by the number of upright scales along the margin 

 of the disk in each interbrachial space ; but I satisfied myself, by counting 

 those of many specimens, that this nuinber varies. Thus, thirteen specimens 

 from Spezia, having disks from 1.2™° to 2.5°""', had from five to eight inter- 

 brachial scales, and the number was not always in proportion to the size of 

 the specimen. Two specimens from the Adriatic, with disks of 2.2°"°- and 

 2.8°"" , had eight, nine, or ten scales. Two from Naples, having disks of 2.2°""- 

 and 3.8°""-, had eight, nine, eleven, or twelve scales. This Chilian specimen, 

 with a disk of 2.5°""-, had nine interbrachial scales. 



Hassler Expedition ; Talcahuano Bay. 



