254 EvaANs: HEPATICAE OF PUERTO RICO 
is represented by a single projecting cell and the second, or proxi- 
mal, tooth is no better developed, the two being separated from 
each other by a slight indentation at the bottom of which a single 
cell of the lobule reaches the margin (PLATE 12, FIGURES 6, 13, 
and 21. Unless careful dissections are made the two teeth present 
the appearance of a single tooth, and the apex might readily be 
described as simply acute. In this type of lobule the hyaline 
papilla is situated in the lunulate sinus, slightly displaced to the 
inner or antical surface. It may therefore be described as distal 
with respect to the apical tooth. The species showing this type 
of lobule are among the most delicate of the Lejeuneae, and it 
seems advisable to segregate them from Cololejeunea as a distinct 
genus, to which the name A phanolejeunea may be applied. 
What may be a third type of lobule is found in the Javan 
Cololejeunea ciliatilobula Schiffn.* In this species the free margin 
of the lobule bears a number of hairlike teeth between the apical 
tooth and the base. Whether this peculiarity is sufficiently dis- 
tinctive to serve as the basis for further segregation is uncertain; 
it is possible that it represents nothing more than an extreme 
manifestation of the tendency noted in Lejeunea laevigata to 
develop accessory proximal teeth. Unfortunately C. ciliatilobula 
is known to the writer from descriptions and figures only. 
In its restricted sense the genus Cololejeunea contains about 
twenty known species. It is quite impossible, however, to give 
more than an approximate estimate because so many have been 
described from sterile or otherwise incomplete material. Itis also 
very probable that many new species may be expected, both here 
and in the genera Leptocolea and Aphanolejeunea. Although the 
genus is largely tropical its range extends well into Europe and 
temperate North America. The northern species grow on rocks 
and on bark. The tropical species occur in similar localities and 
also on living leaves. Certain species are much less particular 
about their substratum than others, the North American C. 
Biddlecomiae (Aust.) Evans, for example, growing on both rocks 
and trees, while the closely allied C. calcarea seems to be confined 
to rocks. The plants are easily overlooked on account of their 
* Conspect. Hepat. Archip. Indici 2'42. 1898. ( = Lejeunea ciliatilobula Schiffn. 
Nova Acta Acad. Caes. Leop.-Carol. 60: 239. pl. ro. f. 11-13. 
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Pa | ne ee 
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eats 
