90 Howe : Phycological studies 



lime between the rays, the Hme-coating often flaking off at matu- 

 rity: disc solitary, nearly flat, 1-2.5 mm. in diameter; sporangia 

 (rays) 6-17 (mostly 11-15), obovoid-clavate to clavate-subfusi- 

 form, 2-3|- times as long as greatest width (which is at two 

 thirds or three fourths of their length), bluntly subcorneal, obtusely 

 taper-pointed, or occasionally rounded obtuse, rather easily sepa- 

 rable and often more or less free on drying, mostly free in mature 

 specimens after decalcification ; coronal processes very small, 

 short-cyHndrical, slightly enlarged at the top and appearing oval 

 or orbicular in surface view, 22-35 n in greatest diameter, each 

 bearing 2 (rarely 3) hairs, hair-rudiments, or hair-scars ; hypopeltal 

 processes wanting : aplanospores i 5-60 in a sporangium, globose 

 or ellipsoid, 68-82 fi in greatest diameter : stipe occasionally cor- 

 rugated and enlarged in the upper part, o. 1-0.2 mm. in maximum 

 diameter. [Plate 6, figures 13-15 ; plate 7, figures 1-4.] 



On a reef, near low-water mark, with Neomeris annulata and 

 Acetabuhivi polyphysoides, Montego Bay, Jamaica, Hoive 502ga 

 (type), January 19, 1907; Mariguana, Bahamas, Howe 5453; 

 Castle Island, Bahamas, Hozve ^yjib. 



Acetabuhim pusilhmi differs from A. polyphysoides, with which 

 it is sometimes associated, in its smaller size, in being strongly 

 calcified throughout, in the character of the coronal processes, 

 which are only 22-35 [i instead of 75-150 fi in diameter and bear 

 only 2 (rarely 3) instead of 5-13 hairs, and in the smaller aplano- 

 spores, which are 68-82 /i instead of 88-190/i in diameter. It is 

 one of the most minute of the species thus far described in the 

 genus, the average diameter of the disc being about 1.6 mm. 



The nearest relatives of Acetabulum piisillum are apparently 

 two East Indian species, Acetabidaria exigiia Solms * and A. 



of botanical nomenclature would prevent the adoption of Acetabuhun. As a matter of 

 fact, the generic name in its original Tournefortian form was used in Boehmer's edition 

 of Ludwig's Definitiones Generum Plantarum (p. 504) in 1760, Tournefort being there 

 cited, as he was cited also by Linnaeus two years earlier, in establishing the binomial 

 Madrepora Acetabulum (Syst. Nat. 793. 1758), so the name is technically free from 

 whatever opprobrium there may be in prelinnaeanism. The generic name Acetabuluin 

 was used also by Lamarck in 1816 (Hist. Nat. Anim. sans Verteb 2 : 149). though 

 this fact has no bearing on the priority question, as it was four years later than Lamou- 

 roux's establishment of Acetabidaria (Nouv. Bull. Sci. Soc. Philom. 3: 185. 1812). 

 However, Olivia (Bertol. Rar. PI. Ital. Dec. 3 : I17. 1810), to which no valid ex- 

 ception can be taken, antedates Acetabularia and must be preferred to it under any en- 

 forcement of priority principles, unless a comparatively modern date betaken as a start- 

 ing point. Under the circumstances, we prefer the original Acetabulum, which has a 

 clear post-1753 claim upon our favor. 



* Trans. Linn. Soc. Bot. IL 5 : 28.//. 2. f. i, 4. 1895. 



