On some new and rare Besmids. By W. B. Turner. 937 



vrith short stout spines ; the end lobe bearing near its extremity a 

 species of annular rugoso-spinous coronet. Picton, Nova Scotia. 

 Fig. 13. 



Long, (semi-cell) 112 /x = • 00441 in. ; lat. 68 yti = -00268 in. ; 

 lat. isthmi 22 /x = • 0008(i in. 



14. M. denticulata Breb. nov. Tar. Minnesotensis. A large 

 and handsome variety; in general contour closely following the 

 type, except the polar lobe, which has pointed extremities, and 

 bears a central terminal inflation ornate with a single series of 

 pearly dots or granules. Minnesota, U.S.A. 



Long. 266 fi = -0105 in. ; lat. 2-52 /x = -0099 in. ; lat. end 

 lobes apic. 68 /x = -00268 in.; lat. isthmi 39 /x = -00154 in. 

 Fig. 14. 



15. M. hrachtjptera Lundell nov. var. lispinata. This beautiful 

 species "was first observed by Lundell in Sweden (Desm. Suec. 

 p. 12, t. i. f. 4, 1871), and was added to the British flora last year, 

 by Mr. John Bisset from the Windermere district.* Of the form 

 shown I obtained several from near Bowness, in August last. The 

 marginal contour in this species is very erratic. The variety figured 

 is not of such " spreading " form as the type, and has two, in lieu 

 of three, spines at the apices of the lobules. 



Long. sin. acul. 191 fx = -0075 in.; lat. 131 fj, = -0041 in.; 

 lat. max. lob. pol. 54 /x = - 00213 in. ; lat. isthmi 37 /i = • 00146 in. 

 Fig. 15. 



16. M. papillifera Breb. nov. var. Novse-Scoticie. In length 

 and breadth about one-sixth larger than the type. General contour 

 following type pretty closely, but the end lobe is very difierent, the 

 two normal digitiform appendages being replaced by broad, pointed 

 elevations ; moreover, in the type the apices of the end lobe are 

 rounded off, in this form they are sharply pointed. Picton, Nova 

 Scotia. 



Long. 152 fji = -00599 in. ; lat. 133 /x = -0052 in. Fig. 16. 



Arthrodesmus Ehr. 



17. A. incus (Breb.) Hassall nov. var. Americanus. Frond 

 swollen at base, and differing from the European type by having 

 pyramidal segments, not oblong-quadrangular as in the familiar 

 form. Harvey Lake, U.S.A. J''i,i^. 17. 



Long. rs. spin.) 30 ytt = -00118 in.; lat. 25 ix = -00098 in.; 

 long. spin. 16 /x = '00063 in. The measure agrees closely with 

 tliat of Dr. liabenhorst in Fl. Eur. Alg. iii. p. "226, and it may 

 possibly be a variety of Dr. ] i.'s " h. forma-semicellulis basi gibbosis, 

 aculeis rectis vel convergentibus," liabh. 1. cit. 



* See this Journal, iv. (ISSI) p. 102. 



