—57— 



plant of the variety cequiloba, collected by Culmann at the Gemmi in Switzer- 

 land, the type locality. All evidently represent the same species. 



In size S. scitulus equals robust forms of S. exsectus or S. exsectcBformis. The 

 plants grow in depressed mats and are dull green, becoming brownish with age. 

 The shoots are prostrate in their older parts and produce rhizoids in abundance ; 

 the apical parts, however, especially if gemmiparous, are ascending and develop 

 few or no rhizoids. The stems, which are usually . pigmented with purplish 

 brown, are about 0.3 mm. in diameter and extend for long distances without 

 branching. 



The leaves are more or less imbricated and spread obliquely (fig. i). The 

 line of attachment of a leaf consists of two parts, which form a broad angle with 

 each other. The dorsal part is short and transverse, while the ventral part is 

 longer and directed obliquely forward, thus making the leaves succubous. When 

 spread out flat the leaves appear oblong-quadrate (figs. 2, 3) and measure about 

 I mm. in length and 0.9 mm. in width. At the broad apex they are subequally 

 three-lobed for about one-fourth their length. The lobes vary from acute to 

 obtuse and the sinuses separating them are rounded. When a leaf is still at- 

 tached to the stem it is usually complicate with a rounded keel, the ventral 

 portion with two lobes corresponding to the longer ventral portion of the line 

 of attachment. In some cases, however, the keel is practically obsolete and the 

 leaf appears explanate. Under these circumstances the transverse attachment 

 at the dorsal base shows that the plant is a Sphenolohus rather than a Lophozia. 

 The leaf cells average about 25 ju along the margin of the leaf and about 28 fi 

 in the median and basal portions; sometimes they are a little longer than broad. 

 The trigones are well developed and occasionally confluent. In most cases 

 they are triangular with more or less bulging sides. Underleaves are not present. 



As in most if not in all members of the genus, 5. scitulus is dioicous. The 

 perichaetial bracts are more closely crowded than the ordinary leaves and are 

 somewhat larger, measuring about 1.3 x 1.2 mm. The ventral lobe tends to be 

 a little larger than the other two, the sinuses are sharp, and the apices of the 

 lobes are acuminate or even cuspidate (fig. 4). In one instance a lobe was ob- 

 served in which a sharp lateral tooth was developed near the apex. There are 

 no bracteoles. The perianth, which measures about 3 mm. in length and i mm. 

 in diameter, is cylindrical, although sometimes slightly dilated in the basal 

 half. In the upper portion it is four- or five-plicate with rounded keels, the 

 latter becoming more pronounced toward the apex, which is not markedly con- 

 tracted. The mouth is irregularly and not deeply cleft, the lobes being more 

 or less denticulate. Most of the teeth are very short, but a few are two or three 

 cells long. 



Although no antheridia were demonstrated in the material examined a 

 few leaves were found which were evidently perigonial bracts. They occurred 

 in small clusters of from one to three pairs and indicated that the male inflores- 

 cence, although at first terminal, soon became intercalary through proliferation. 

 The bracts resemble ordinary leaves in most respects but are saccate at the 



