4 SMITH SON [AN MISCELLANEOUS COLLECTIONS VOL. 98 



acanthostyles lack the tylote modification, and the microscleres 

 are of two size ranges (60 micra and 23 micra). 



i, Merriamium maculatum was described as Ectyodoryx m. by 

 Hentschel, 191 1, p. 342, from West Australia. The ectosomal 

 spicules are hastate tornotes with swollen ends. The endosomal 

 spicules range from smooth styles 10 by 244 micra to acantho- 

 styles 9 by 120 micra. The microscleres are commonplace. 



j. Merriamium paupertas was described as Hymeniacidon p. by Bow- 

 erbank, 1866, p. 223, from Great Britain. Various authors re- 

 port it from many locations in the North Atlantic. The ec- 

 tosomal spicules are hastate tornotes. The endosomal spicules 

 are acanthostyles ranging from shorter ones entirely spined to 

 longer ones partly smooth. The microscleres are very much 

 like those of roosevelti. 



k. Merriamium sophium was described as Espcria s. by Fristedt, 

 1887, p. 451, from the Arctic. The ectosomal spicules are 

 strongyles, with ends sometimes microspined. The endosomal 

 spicules are acanthostyles up to 578 micra long. The micro- 

 scleres are, as in all this genus, arcuate isochelas. 



/. Merriamium stylodermam was described as Lissodendoryx s. by 

 Hentschel, 1914, p. 101, from the Antarctic. The ectosomal 

 spicules are hastate tornotes. The endosomal spicules are 

 acanthostyles only partly spined, 15 by 284 micra. The micro- 

 scleres have a very peculiar shape. 



m. Merriamium tortugaseusis was so described by de Laubenfels, 

 1936, p. 83, simultaneously with the establishment of the genus, 

 and is the genotype. It is from the West Indies. The ectosomal 

 spicules are hastate tornotes. The endosomal spicules are thin 

 acanthostyles, 5 by 180 micra. The microscleres are com- 

 monplace for the genus. 



It may be noted that the generic characteristics include a principal 

 (endosomal) skeleton of spiny monactinal spicules with a special der- 

 mal skeleton of smooth diactines, and microscleres that are exclusively 

 arcuate isochelas. 



KEY TO THE SPECIES OF THE GENUS MERRIAMIUM 



(The letter in parentheses following each species name corresponds 

 to the lettering of the species in the review of the genus Merriamium 

 just preceding.) 



