UNKNOWN ATLANTIC OR WEST INDIAN PORITES. 83 



frequent.* Elsewhere the stems are long with curves due not only to aborted forkings but 

 also to the bending upwards of diverging prongs. The living layer iu the looser peripheral 

 stems is from 5 to 6 cm., Ijut in the crowded central stems between 3 and 4 cm. deep. Epithecal 

 films appear. 



The calicles are uniformly about 1 mm. in diameter, nearly flush with tlie surface, except 

 at the growing tips, and polygonal. The walls are a tall, thin, open latticework showing from 

 above as a zigzag thread, smooth, neatly filamentous, sometimes thin. The septa branch off 

 from the walls as smooth filaments, but mostly soon swell into frosted or sharply echinulate 

 granules ; at a lower level the septa join a smoothly filamentous columellar tangle, which is 

 either a ring surrounding a deep open fossa {"2)etite fossettc "), or a true tangle with a 

 columellar tubercle rising from it. A ring of five'pali rises from this tangle as large ecliinulate 

 knol>s or rods. Their symmetry and order are obscured liy the loose open textme of the 

 skeleton, which allows one to see down into the depths of the coral. 



This is the description of the type of Lamarck's Poritcs furcata. The original stock (in 

 the Paris Museum) appears to have been an immense tangle of crowded stems, the bulk of 

 wliich were kept together by being embedded in some cement. Great fragments of it have, 

 however, again become loose. The piece figui-ed by Milne-Edwards is one such, probably from 

 near the centre of the stock, for the branches are densely crowded and fused together. Other 

 fragments much more open, and even dendi'oid, are preserved ; one such. No. Z 182 d, and 

 here figured, was found classed among the Porites clavaria. 



Lamarck referred to the specimen figured by Morison (Plant Hist. iii. sect. 15, plate x. 

 fig. 12) in 1699, as a possible synonym. That specimen seems to have been in the Ashmolean 

 Museum, Oxford. Inquiries at Oxford have so far elicited no information. The figiu'e suggests 

 a Pocillopora rather than a Porites. 



Referring to the specimen itself and its^type of growth, we see how unfounded is the 

 suggestion which has been adopted by so many recent writers that Lamarck's Poritcs furcata 

 represents a different type of growth-form from clavaria. If there is to be a furcate type, let 

 there be one by all means, but let it be understood that it does not rest upon Lamarck's coral- 

 It may be an advantage to have a clavate, a furcate, and a divaricate type of stock, including 

 respectively, forms which fork at short distances, at medium distances, and at long distances 

 apart. If so, they should be deliberately adopted as so many convenient descriptive terms 

 required by the modern analysis of the differences discoverable in the specimens, without any 

 implied relationship with Lamarck's or Lesueur's specimens. 



Lamarck included in the same " species " another coral as a variety which is also, fortu- 

 nately, still preserved in the Paris Museum as No. Z 187 a. This will be described under a 

 different heading, see next page. It helps to explain Lamarck's text. 



The concluding observation to the P. West huUes x. 2, applies to this coral as well. 



* The figure given by Milne-Edwards represents fragments from the crowded centre of a large 

 stock. 



u 2 



