Order COMATULIDA A. H. Clark (continued) 



The general account of this order, with the diagnosis, synonymy, range, and 

 keys to the included families and higher groups, will be found in Part 3, pp. 69-74. 



Suborder OLIGOPHREATA A. H. Clark (continued) 



The synonymy, diagnosis, range, and history of this suborder will be found in 

 Part 3, pp. 74-76. 



Superfamily MARIAMETRIDA Gisldn 



Mariametrida GISLN, Zool. Bidrag Uppsala, vol. 9, 1924, pp. 230, 233, 235, 237, 240; Arkiv for 

 Zool., vol. 19, No. 32, 1928, p. 4. A. H. CLARK, Rec. Indian Mus., vol. 34, pt. 4, 1932, p. 554; 

 Treubia, vol. 14, livr. 2, 1933, p. 211. GisLfiN, Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 

 45, No. 11, 1934, pp. 7, 49. A. H. CLARK, John Murray Exped. 1933-34, Sci. Reports, vol. 4, 

 No. 4, 1936, p. 88. H. L. CLARK, Mem. Mus. Comp. Zool., vol. 55, 1938, p. 42. 



Diagnosis. A superfamily of the suborder Oligophreata (see Part 3, p. 74) in 

 which there is no comblike structure on the distal portion of the oral pinnules; the 

 distal pinnules are never prismatic; the genital pinnules are never prismatic, though 

 occasionally a few of the basal segments may be carinate; the oral pinnules, which 

 may be long or short, slender or stout, or stout basally and slender distally, very 

 flexible to stiff and spinelike, composed of long or short segments, usually show some 

 distinct trace of carination on more or fewer of the basal segments, and are some- 

 times sharply prismatic throughout; and the mouth is always central or subcentral, 

 the anal tube being more or less marginal. Sacculi are always present, though often 

 in small numbers. The arms vary from 5 to 100 in number but are usually between 

 15 and 40, though not infrequently 10. 



Remarks. The superfamily Mariametrida as herein understood includes the 

 families Zygometridae, Eudiocrinidae, Himerometridae, Mariametridae, and Colobo- 

 metridae. In addition to these Gislen included also the family Tropiometridae, 

 which seems to me to be quite out of place here, its prismatic pinnules, very broad 

 division series and first two brachials, ambulacral deposits, and cirri indicating a 

 rather close relationship to the Thalassometridae and Charitometridae. 



The family Zygometridae as understood by Gislen included the genus Eudiocri- 

 nus, which is herein set apart as a distinct family. The family Stephanometridae, 

 which was included in the Mariametrida by Gislen, is here merged with the Maria- 

 metridae. 



Within the superfamily Mariametrida the families Zygometridae and Eudiocrini- 

 dae agree, but differ from the other families, in having a syzygy between the elements 

 of the IBr series, and also in having a more or less completely plated disk, although 



74 



