TUNICATA. 
103 
Family Octacnemidce, includes 0. bythins, a deep-sea Salpid, in which 
the body forms a flattened disk produced into eight radiating lobes. 
Fig. 22. 
Salpa runeinata-fusiformis. A. Chain form. B. Solitary form. 1-9, muscle 
bands ; em, embryo ; m, mantle ; vise, visceral mass or nucleus. 
(Herdman : Tunicata, Encyclopaedia Britannica.) 
Fig. 23. 
h st 
Doliolum denticulatum, sexual generation, from the left side. 
m 1 -™ 8 muscle bands ; at, atrial ; br, branchial apertures ; br s, branchial 
sac ; sg, stigmata ; st, stomach ; ng, nerve ganglion ; so, sense organs. 
(After Herdman, Encyclopaedia Britannica.) 
Family DolioMdm. The body is cask-shaped and surrounded by 
circular hoops. The branchial and atrial orifices are at the opposite 
