New undescribed species record for Gulf of Mexico, JFPC 0001, examined by J. Pilger; from D. Felder sample site NSF-II-043; anterior proboscis missing; longitudinal muscle bundles absent; likely an undescribed Thalassema sp. but differing from T. hartmani and T. philostracum in having uncoiled nephrostome threads instead of leaf-like nephrostome; also included is specimen USNM 66739 previously misidentified by J. H. Baker as Urechis sp.; correction reported to USNM.
Added keyword "endemic to Gulf of Mexico"
Pilger, J. F. 2009. Echiura of the Gulf of Mexico, Pp. 797–802 in Felder, D.L. and D.K. Camp (eds.), Gulf of Mexico–Origins, Waters, and Biota. Biodiversity. Texas A&M Press, College Station, Texas.
Harte Research Institute for Gulf of Mexico Studies. 2016. GulfBase: Resource Database for Gulf of Mexico Research, Education, and Management. Texas A&M University-Corpus Christi. World Wide Web electronic publication. http://www.gulfbase.org, 10-16-2019.