dolichurus (dolikurus)

[NL., IMG:content-3004.jpg:[subsumed][subsumed][subsumed][subsumed][subsumed][ocr errors][subsumed][merged small] Sexual Ascidiozoöid of Doliolum denticulatum, highly magnified. a, ganglion; c, endostyle; d, oral opening (atrial opening at opposite end); g, esophagus; i, stomach; 1, intestine; P, P, P, testis; r, heart; t, t, muscles. free-swimming, cask-shaped organisms, moving by contracting the body and so squirting water out of one or the other end, developing by an alternation of generations, and provided with ciliated ribbon-shaped branch iæ, dividing the respiratory cavity into two portions. The branchial lamellæ are pierced with numerous slits. In sexual generation the ovaries and testes mature simultaneously.