XXX. Didymoclon. Fruitstalk terminal. Peristome single, of 16 teeth, cleft to the very 'oase, or nearly so, or 32 approachinE,, in pairs, or united at the base. Calyptra dimidiate.
Contains eight British species, of which the most rare, at least in fruit, D. flexifolium, was found abundantly in that state last summer, by INir. Greville, in Devonshire, with the teeth in good condition, and the genus of this moss no lon,ger remains uncertain. D. inclinatum, and D. rigidulum, are also rare. The Masc. Exot. contain two IICW species, besides D. splachnifolium, which is the NVeissia obtusa of Bride).
XXX. Funaria. Fruitstalk terminal. Peristome dou ble, oblique; the outer of 16 teeth ; the inner of 16 teeth, opposite those of the outer.
Three British species belong to it, of which F. hiber nica, " found on the roof of a thatched cottag-e at Blarney, near Cot k." by 'Mr. Drummond, is the rarest.
XXXII. Zygodon. Fruitstalk terminal. Peristome Xxxii. Zygodon. Fruitstalk terminal. Peristome elouble; the exterior of 16 teeth, approaching in pairs ; the interior of as many horizontal cilia. Calyptra dimi diate, short.
Contains only one British species, Z. conoideum, which grows always on trees, and has been found near Inverary, Scotland, by Mr. Dickson ; in Mr. Templeton's orchard at Orange-grove, Ireland ; and ncar mchester, hy Mr. Hobson. Another species, Z. ohtusifolium, sent from Nepal by the Hon. Colonel Garner, is figured in the Exot.
XXXIII. Orthotrichum —Fruitstalk terminal ; PeXxxiii. Orthotrichum —Fruitstalk terminal ; Pe- ristome double, exterior of 16 teeth, a pproaching- in pairs; the interior consisting of 8 or of 16 cilia, or %yarning. Calyptra mitriform.
Ten British species belong to it, of which the last dis covered and rarest is O. Lyellii, found by. Mr. Lyell " on trees in the New Forest, Hants." 0 Hutchinsix is the only other rare species, and is exclusively, or chiefly, Irish. Nine new species are figured in the Alusci Exot.
XXXIV. Sclotheimia. Fruitstalk terminal. Pcristome Xxxiv. Sclotheimia. Fruitstalk terminal. Pcristome double ; exterior of 16 revolute teeth ; the interior a co nical plaited membrane, irregularly torn.
A tropical genus very nearly related to Orthotrichum. The only species of it figured in the Alusc Exot. Scl. sulcata, was sent from Nepal by the Hon. Colonel Gar ner, and " has such a resemblance to Orthotrichum longifolium, that it can be distinguished only by the Pe ristome." The genus seems to have been first charac terized by SCI1NS aergrichen.
XXXV. Neckera. Fruitstalk lateral ; the exterior Xxxv. Neckera. Fruitstalk lateral ; the exterior of 16 erect free teeth ; the interior of 16 cilia, connected only at the very base by a short membrane ; Calyptra dimidiate.
Contains two British species, of which N. pumila is rare in Scotland ; nor is the fruit of N. crispa abundant. Eight new species, and three that had been previously figured, have place in the Alusci Exotici. It is proper to remark, that the character ol the genus, as given in the Alusci Exot. is more extensive than that in the Alusco logia Britannica, which we have here exhibited ; and hence it is not impossible that some of these species may belong to the following genus.
XXXVI. Anomodon. Fruitstalk lateral ; peristorne Xxxvi. Anomodon. Fruitstalk lateral ; peristorne double ; consisting of 16 teeth, and a ciliary process ansing from tne side of each tooth; calyptra dimidiate.
Contains two British species. The fruit of A. curd pendulum is rather rare.
XXXVII. Daltonia. Fruitstalk lateral ; peristome Xxxvii. Daltonia. Fruitstalk lateral ; peristome double, consisting of 16 teeth, and a ciliary process aris ing from the side of each tooth ; calyptra rnitriform.
Contains two British species, both of which are rare.
XXXVIII. Fontinalis. Fruitstalk lateral ; peristome Xxxviii. Fontinalis. Fruitstalk lateral ; peristome double ; the exterior consisting of 16 teeth, the intcrior of 16 cilia, connected by transverse bars, and forming a reticulated cone; calyptra mitriform.
Of this genus three species are British ; of which F. capillacea is of extreme rarity, and F. squarnosa some what rare.