188 MADEEPOEAEIA. 



202. Madrepora procumbens. (Plate XXIX. fig. D.) 



Madrepora procumbens, Brook, Ann. Mag. N. H. 1891, vol. viii. p. 467. 



Corallum prostrate or subprostrate, subdivisions free. Branches up to 16 cm. long and 

 1 cm. thick, bearing ramiculi 1"3 to 3"5 cm. long, each of which is usually produced from a 

 single tubular corallite by the formation of radial corallites upon it, nariform or tubo- 

 nariform at first, but becoming spreading tubular, 4 to 9 mm. long. There may be 30 

 or more on a twig 3 cm. long, radiating in all directions, the longer ones arched and bearing 

 very short nariform buds. The stem and main branches bear a few corallites at irregular 

 intervals, nariform or subimmersed and immersed. The elongate tubular corallites are 2 mm. 

 diameter near the base, and 1*5 mm. at the apex. Apex suddenly contracted; aperture 

 small, enclosing a star of 6 well -developed septa. Corallum dense; surface finely echinulate, 

 not pitted ; wall echinulate in rows. 



This species comes near to M. longicyathus, and may prove to be only a well-marked variety 

 of it. It differs, however, in habit and in the arrangement and number of the corallites on 

 the branchlets ; the axial corallites also usually bear buds to within 2 mm. of the apex, 

 whereas in M. longicyathus the terminal 7 mm. is usually free. In one specimen the 

 branches extend horizontally, in another obliquely. 



South Seas, Fiji. 



a. South Seas. Purchased. 41.12.11.3.1 



b. Fiji. Purchased. 62. 2. 4. 33. ^Types. 



c. ? Purchased. 43. 3. 6. 131. J 



B. Corallum stout and lax arborescent, mth slender spreading twigs resembling 



those of Section A. 



203. Madrepora horrida. 



Madrepora Jiorrida, Dana, Zoophytes, p. 472, pi. xxxix. fig. 2 ; M.-Edwards & Haime, Coralliaires, t. iii. 

 p. 140 ; Verrill, BuU. Mus. Comp. Zool. 1864, vol. i. p. 41 ; Rathbun, Proc. U.S. Nat. Mus. 

 1887, vol. X. p. 16 (rum B.-Smith, Ann. Mag. N. H. 1890, vol. vi. p. 452). 



Coralliun large and stout arborescent, divaricately and remotely branched ; branches, 

 below, 2"5 to 5 cm, thick, nearly terete, curved, gradually attenuate, throughout very pro- 

 liferous, with divaricate ramiculi, 25 to 6"75 cm. long. Axial corallites about 2 mm. diameter, 

 exsert ; wall not incrassate. Radial corallites thin tubiform, divaricate, sometimes recurved, 

 very unequal, some 8 mm, long, many much shorter or obsolescent, others proliferous. Star 

 6-rayed. (Dana.) 



A small specimen is in the Collection from Fiji which agrees well with the apical 

 portion of Dana's figure. It has the same appearance as one would expect a young colony of 

 the species to present, but owing to the absence of stout main branches there is at first sight 

 little resemblance to the specimen figured by Dana. 



Pacific Ocean : Fiji, ? Arafura Sea, 



a. Fiji. F. M. Rayner, Esq. [P.]. 62. 2. 4. 29. 



? b. Evans Bank, 15 fath,, Arafura Sea. H.M.S. ' Penguin.' 92. 4. 5. 9. 



