CAPE vp:rde islands PORITES. 27 



height, they are very irregular and unlike those of any of the Indo-Pacific forms. The ragged 

 walls have a general habit not unlike those of a small Alveopora. It is not the Porites called 

 "guadalupensis" by Duchassaing and Michelotti, after the island where it was found; 

 see the description and figure of that form, p. 45, PI. II., figs. 2 and 3, which more closely 

 resembled the typical astrccoides of authors. 



Specimens of tliis coral associated with the next occur in rock pools, forming bright 

 yellow or pinkish-white rounded masses.* 



a. Zool. Dept. 80. 11. 25. 18. (part). 



3. Porites Cape Verde Islands 2- {P- Insularum Arsinarii secunda.) 

 (PI. I. fig. 3 ; PI. XVII. fig. 2.) 



[St. Vincent, coll. H.M.S. ' Challenger ' ; Britisli Museum.] 



Syn. Porites superjkialis Quelch {non D. & M.), Chall. Rep. xvi. (1886) p. 182. 



Description. — The corallum is encrusting, and, by enveloping foreign bodies, forms rounded 

 nodules with smooth surface flattened here and there into facets. The epitheca is everywhere 

 visible round the thin edges. 



The calicles are visible owing to the slight irregular pitting of the fossae, though without 

 sharp outlines to the pits ; these are very variable in size, the larger being about 1'5 mm. 

 The walls are low and broad, and are built up of horizontal, finely cut flakes perforated with 

 rounded pores ; down the sides of the stock the uppermost layer of flakes tends to be rather 

 more filamentous. The septa run out long, straight and narrow (that is, losing their flaky 

 character) from different levels of the wall flakes, and have regular smooth fine echinulae 

 projecting from each side. The echinulation of the septal edges is in striking contrast with 

 the smoothness of the pores and the excisions in the edges of the wall flakes. The septa fuse 

 irregularly above a large, solid-looking plate, which early closes the base of the fossa. Pali are 

 hardly traceable, but a slight very irregular columellar tubercle may appear in the shallower 

 calicles round the creeping edges. 



The original description of Porites superficialis from St. Tliomas (see below p. 59) 

 hardly agrees with this, for its septa were laterally smooth, or hardly echinulate ; whereas 

 the septal echinulae are here pronounced. 



This again hardly fits in with the P. astrceoides group, which is the only species 

 established by Drs. Gregory and Vaughan for the West Indian, and I may add Atlantic 

 massive and encrusting Porites, see Introduction, p. 10, nor is it one of our astneoid group, 

 (see p. 142). 



It is described as occurring in rock pools in association with the form last described 

 (v. footnote). 



a. Zool. Dept. 80. 11. 25. 18. (part). 



* See Moseley, " Notes by a Naturalist on the ' Challenger,' " p. 48. Quoted by Mr Quelch. 



B 2 



