West-Indian Species of Matliepora. 23 



<lifficulty, tliough fragments may sometimes be indeterminable. 

 But tlu' two forms are sufficiently allied for their separation 

 to he a nuMC matter of convenience. 



The diirerence between M. pahnata and M. cervicornis is, 

 however, tar more definite, and Pourtales had no hesitation 

 in keeping them distinct. Brook *, however, unites them on 

 the ground that " Pourtalbs has pointed out, with regard to 

 the West-Indian specimens of juilnuitu, cervlcornii, and pro- 

 Ufera, that the projier iiabit and robustness of each form is 

 associated with a difierent position on the reef. M. pahnata 

 grows in situations exposed to the force of the sea ; M. cervi- 

 cornis m less exi)Osed localities; while for its full develop- 

 ment M. proUfera aj)pears to require sheltered spots on the 

 inner side of the reef.'" This passage involves another 

 unfortniiate misrepresentation of Pourtales, for, according to 

 that author, the species which "requires a rather sheltered 

 position for its full development " f is M. cervicornis^ and not 

 M. prolifera. In respect to the position of growth of the 

 latter, Pourtalcis gives no information ; and, so far as my own 

 observations go, M. prol'ifera does not flourish in sheltered 

 spots inside the reef, but in deeper water than M. cerclcornis, 

 and often outside the main reef. Thus the typical species in 

 the quiet coves of Parham Sound, Antigua, are J/, pahnata 

 and M. cervicornis. The best specimens of J/, prolifera that 

 I obtained from Antigua came from the depth of 3 fathoms 

 from aji exposed position on the slopes of Sandy Island. 



Pourtales did say that ^f. pahnata is characteristic of the 

 exposed ]jositions on the outside reefs, a statement, however, 

 which is only true with one important limitation. The 

 particular form of J/, palmata known as " the car of Neptune," 

 w hich has a massive corallum formed of thick lamellar ex- 

 pansions, is no doubt the typical form of Madrepora found in 

 exposed positions in the West-Indian reefs. The fragile 

 branched coralla of M. cervicornis antl M. proh'fera would be 

 shattered if struck by the full force of a breaker ; they accord- 

 ingly grow in jnotected situations or at a depth below the 

 limit of the surf. 



It is jiossible that it was the " Neptune's car" ioxmoi palmata 

 ■which Pourtales had in mind when writing the previously 

 quoted remark. His statement, so far as my observations go, is 

 not correct for M. pahnata as a whole. The alciforni variety 

 oi palmata, which both Pourtales and Brook include in that 

 form, grows under iilentically the same conditions as M. cervi- 

 cornis. For example, I collected specimens of both forms 



* JJrook, <'p. (it. p. 1*8. 

 t Piiuitnlt'.-*, op. cit. p. 84. 



