76 PROCEEDINGS OF THE ACADEMY OF [1889. 



VARIATION IN OPHIURA PANAMENSIS AND OPHIURA TERES. 



BY J. E. IVES. 



Among the Ophiurans in the collection of the Academy there are 

 a number of specimens from the Pacific Coast of North and Central 

 America which appear to me to belong respectively to Ophiura 

 Panamensts Liitken and Ophiura teres Lyman. I have had occa- 

 sion, while identifying these forms, to correlate the descriptions of 

 Messrs. Liitken, Lyman & Verrill (Liitken, Vidensk. Selsk. Skrift. 

 1850, p. 193 ; Lyman, Proc. Bost. Soc. N. H. vii, pp. 198, 257, 1860, 

 and 111. Cat. Mus. Comp. Zool., No. 1, pp. 32, 37, 1865; Verrill, 

 Trans. Conn. Acad., i p. 253), and as the specimens above mentioned 

 appear to add to our knowledge of the variation in color and pattern, 

 I propose, therefore, to briefly consider some of the characteris- 

 tic features of these two species. In addition to the specimens in 

 the collection of the Academy I have had the opportunity of ex- 

 amining three specimens kindly loaned by the Museum of Compara- 

 tive Zoology. Mr. W. N. Lockington, who made a study of 0. Pan- 

 amends during his residence on the West Coast, has also courteously 

 placed at my disposal some manuscript notes. 



The different varieties of 0. Panamensts appear to range them- 

 selves into two groups, as follows : 



1. Upper surface of disk dark green, greenish gray or brownish, 

 sometimes speckled with darker, and sometimes with a white mark 

 in the center ; upper surface of arms, same, banded with lighter and 

 darker, with outer edges of upper arm-plates occasionally marked with 

 dark longitudinal lines, presenting a toothed appearance (Panama 

 to Cape St. Lucas). 



2. Disk olive green, mottled with black and red, or of various 

 shades of brown; arms, same, banded with lighter ; darker bands 

 sometimes mottled with lighter, and the light bands so dark as al- 

 most to obliterate the banding. (West Coast of Mexico, Lower 

 California and California.) Mr. Lockington records a variety with 

 a brown disk and olive green, arms without bands except at the tips. 



The various specimens of this species agree in having the upper 

 arm-plates little or not at all broken ; the radial shields naked and 

 the mouth shields about as long as broad, convex outwardly and 

 with a slight, rounded angle on the inside. The larger specimens 

 have eleven arm spines at the base of the arm. 



