1907.] FROM THE CAPE VERDE ISLANDS. 495 



and of the fixed gonophore, this genus has been inckided in the 

 family Clavidse, although the simplicity of the gonophore and the 

 complexity of the branching almost warrant the formation of a 

 new family. 



SoLBNiopsis DENDRiFORMis, sp. n. (Plate XXYI. fig. 1; text- 

 figs. 142, 143.) 



The colonies for which this species has been formed were 

 found at two localities. The solitary colony from Boa Yista is 

 the largest of the series, almost 10 cm. high, with a thick, fascicled 

 stem which is, towards the base, covered by a mass of ramifying 

 tubes, forming a spongy tissue through which here and there a 

 hydranth projects. This loosely-built basal mass attains a 

 diameter of 1 cm. From this stem, which in transverse section 

 shows a small central strand of chitin with a few minute coenosarc- 

 containing canals, surrounded by many parallel tubes which again 

 are surrounded by irregularly arranged, loosely aggregated tubes, 

 the branches arise approximately in one plane. The colonies 

 from St. Vincent are smaller, only 6 cm. high, and lack the 

 spongy basal thickening, possessing a cylindrical stem 2 mm. in 

 diameter, composed of closely packed parallel tubes. From these 

 stems, as from that of the previous specimen, flabellate branches 

 lying generally in one plane arise. The primary branches bear 

 alternate secondary branches, and these again may bear tertiary 

 branches, all of these appearing to be fascicled owing to the 

 apposition of several tubes. Single, monosiphonic bi-anches, how- 

 ever, arise alternately in one plane, for the most part from 

 branches of the second and third order, and from the distal end of 

 these the hydranths project. 



The mode of branching is peculiar. In the less strongly 

 fascicled portions of the stem two or three perisarcal tubes lie 

 alongside of, and inseparably united to, one another, each con- 

 taining a strand of coenosarc. Some considerable distance before 

 a free braijch originates (frequently 20 or 30 mm.) one of the 

 outermost strands divides into two, and round the new coenosarcal 

 division a chitinous tube is formed, wedged in between the old 

 tiibes. Thus the number of parallel-lying and united tubes is 

 increased, but finally, after a course of some 2 or 3 cm., the outer- 

 most of the two portions into which the original strand divided 

 becomes free to form a branch, and the number of tubes in the 

 fascicle is thus reduced. The ccenosarc of the free branch divides, 

 as did that of the stem, and becomes ensheathed in several united 

 tubes which, on bending outwards and becoming free, form new 

 branches or hydranth- bearing ramuli. The division of the coeno 

 sarcal strands, and consequently the origin of the branches and 

 ramuli, takes place alternately, first on one side, then on the 

 other. 



The hydranths project from simple, alternate ramuli 0*4 mm. 

 in diameter. Extended they are long and slender, 2*0 mm. by 

 "2 or 0*3 mm., almost cylindrical, with a prominent club-shaped 



Proc. Zool. Soc— 1907, No. XXXIY. 34 



