III ASCIDIAE SIMPLICES—MOLGULIDAE WG 
Fam. 4. Molgulidae.—‘Solitary sessile Ascidians, sometimes 
not fixed; branchial aperture six-lobed, atrial four-lobed. Test 
usually encrusted with sand, which is generally attached to 
Fia. 40.—Three simple Ascidians with vascular adhering processes from the test (nat. 
size). A, Ascidiella aspersa, O. F. Miiller; B, Ciona intestinalis, Linn.; C, 
Molgula oculata, Forb. 
branched hair-like processes from the test (Fig. 40,C). Branchial 
sac longitudinally folded; stigmata more or less curved, usually 
arranged in spirals (Fig. 41); tentacles compound. The chief 
ih 
Si AN i 
Fic. 41.—Branchial sacs of Molgulidae showing curved stigmata. A, Ascopera gigantea, 
Herdman ; B, Molgula pyriformis, Herdman ; C, Lugyra kerguelenensis, Herd- 
man, 
genera are—WMolgula, Forbes (Fig. 40, C), with distinct folds in 
the branchial sac (Fig. 41, B), and Lugyra, Ald. and Hane.,. 
with no distinct folds, but merely broad internal longitudinal 
bars in the branchial sac (Fig. 41, C). In some of the Molgulidae 
