REPORT ON THE TUNTCATA. 
375 
In the Didemnidae there is one abyssal form, Leptoclinum tenue, but four other species 
extend to depths of over 100 fathoms. 
If the range of depth at which Compound Ascidians were found (from the shore 
down to 1600 fathoms) be divided into zones, the following results will be arrived at : — 
I. — Between the shore and 50 fathoms sixty species and varieties were found, viz.: — 
Botrylloid.es tyreum. 
,, perspicuum. 
,, ,, var. rubicundum. 
„ nigrum. ■ 
Polycyclus jeffreysi. 
Colella pedunculata. 
„ ihomsoni. 
,, gaimardi. 
,, pulchra. 
,, elongata 
„ quoyi. 
,, murrayi, var. ruhida. 
„ concreta. 
Distaplia vallii. 
iy) pyriformis. 
Cystodytes philippinensis. 
Symplegma viride. 
Tylohranchion speciosum. 
Atopogaster elongata, var. pallida. 
Morchellioides affinis. 
Morchellium giardi. 
Polyclinum pyriforme. 
,, fungosum. 
,, depressum. 
„ minutum. 
Aplidium fuscum. 
,, leucophceum. 
„ crassum. 
,, fallax. 
„ fumigatum. 
Amaroucium variahile. 
„ ,, var. tenerum 
,, globosum. 
