STOMATOPORA DILATANS. 429 



Geographical Distribution. Bergen (A. M. N.) : 

 Roscoff (Jolict). 



Range in Time. Coralline and Red Crag, on shell (S. 

 V.Wood). 



Stomatopora DILATANS, Jolinston. 

 Plate LVII. figs. 3, 3 a. 



Alecto DILATANS, Johnsf. B. Z. ed. 2, 281, pi. xlix. figs. 5, 6 : Bzcsk, B.M. 



Cat. iii. 24, pi. xxxii. fig. 2 ; Crag Pol. 112, pi. xx. figs. 6, 7 ; 



Landsb. Pop. Hist. 280 : Normaii, Shetland Dredgiug-List, 



Kep. Brit. Assoc, for 18fi7 (1868), 310. 

 ? DiASTOPORA REPENS (part.), Smift, loc. cit. 395 and 416, pi. riii. figs. 1-4. 

 ?Alecto REPENS, Mamoiii, Brj'oz. d. Castrocaro, pi. vi. fig. 72. 



Zoarium entirely adherent, slightly ramified^ consisting of 

 a short stem, from which two or three long, widely di- 

 vergent, serpentine branches originate, which sometimes 

 bifurcate at the extremity ; branches convex, rounded, 

 often constricted at intervals^ enlarging towards the 

 end, so as to assume a clavate form. Zocecia rather 

 slender, laid closely side by side in many series (7-8 in 

 the expanded portions), occupying the whole of the 

 front of the branch, commonly alternate, punctate, 

 vitreous, and of a delicate whiteness ; orifice raised, 

 but usually projecting very slightly. Ocecia at the 

 extremity of the branches. 



This species differs from the preceding in its mode of 

 branching, which is usually much simpler than that of 

 S. major, in the character of its branches, which are long 

 and serpentine, not depressed, and decidedly clavate at the 

 extremities, and in the arrangement of the cells^ which 

 are slender, horizontal^ not disposed in companies of two, 

 three, or four, but packed closely together and occupying 

 the whole front surface of the branchy slightly raised 

 towards the orifice, and of singularly delicate texture. 

 The branches are usually (so far as I have seen) few in 



