450 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
Family PYURIDAE Hartmeyer, 1908. 
[= CYNTHIIDAE s. HALOCYNTHIIDAE auct. plur.]. 
Genus Pyura Molina, 1782. 
[ = Cynthia s. Halocynthia auct. plur.]. 
29. Pyura echinata (Linnaeus), 1767. [Cynthia echinata Verrill + Ascidia 
hirsuta Agassiz]. 
Circumpolar in the Arctic Seas; northern waters of Europe; Iceland, 
Greenland; on the American Atlantic coast south to off southern Massa- 
chusetts and Rhode Island. 
Low water to 109 fathoms. 
30. Pyura ovifera (Linnaeus), 1767. [Bollenia bolteni + B. rubra + B. 
reniformis, etc., auct.]. Sometimes called stemmed sea peach. 
Circumpolar in the Arctic seas; on the American coast ranging south 
to Nantucket Shoals (DeKay gives a record from New York Harbor). 
Shallow water to 100 fathoms. 
31. Pyura aurantium (Pallas), 1787. [Cynthia or Halocynthia pyriformis 
Verrill]. Popularly called sea peach. 
Nearly circumpolar in the Arctic seas; on the American coast south 
to Massachusetts Bay. 
Low water to 120 fathoms. 
Genus Microcosmus Heller, 1877. 
32. Microcosmus nacreus, sp. no v. 
Between Nova Scotia and Sable Island, also on Grand Bank. 
26 to 36 fathoms. 
Genus Culeolus Herdman, 1881. 
— . Culeolus suhmi Herdman, 1881. [Culeolus Tanneri Verrill]. 
Deep water off the eastern LTnited States. 
1,608 to 2,620 (probably to 2,919) fathoms. 
Family TETHYIDAE Hartmeyer, 1908. 
[ = STYELIDAE auct. plur.]. 
Genus Pelonaia Goodsir and Forbes, 1841. 
33. Pelonaia corrugata Goodsir and Forbes, 1841. [Pelonaia arenifera 
Stimpson]. 
Nearly circumpolar in the Arctic seas; northern Europe, including 
the British Islands; Iceland; Greenland; Labrador; Gulf of Saint 
Lawrence; once recorded from Massachusetts Bay. 
6 to 100 fathoms. 
