Dichrometra A.H. Clark, 1909d

Mohammednowshad, B., Idreesbabu, K. K., Parameswaran, Usha V., Messing, Charles G. & Sureshkumar, S., 2020, The Shallow-water Crinoid Fauna of Lakshadweep Atolls, North-western Indian Ocean, Zootaxa 4789 (1), pp. 247-265 : 257-258

Dichrometra A.H. Clark, 1909d

Type species.— Alecto flagellata Müller, 1841 .

Diagnosis.— A genus of Mariametridae with centrodorsal discoidal, with aboral pole flat, slightly concave or convex; brachitaxes laterally separated and aborally rounded to closely apposed and flattened laterally; adambulacral processes absent; cirrals <40; distal cirrals smooth, or with aboral keel, or blunt or sharp aboral spine; P2, or P2 and P3, larger and longer than both P1 and following pinnules, and tapering distally to slender, often flagellate tip; either P2 or P3 longest and stoutest, or of similar length and strength; enlarged oral pinnules with articular facets not reduced or modified, proximal segments carinate or not, and with LW of middle pinnulars at most 2.0; P2 usually of 20 or more pinnulars (maximum 40); up to 50 arms (usually 20–40) (modified from Rankin and Messing, 2008; Taylor et al., 2017).

Remarks.— Taylor et al. (2017) synonymized Lamprometra A.H. Clark, 1913c , and Liparometra A.H. Clark, 1913c , under the senior Dichrometra . The three genera had been distinguished on the basis of differences in the relative lengths and robustness of P2 and P3.