936 Transactions of the Society. 



longer than broad ; lobes well defined, eacb with a coronet of large 

 protuberant gemmules, some of which are rather spiniform ; smooth 

 or obscurely punctate ; on the front of segments, at the base of 

 polar lobes, two series of four granules arcuately arranged. The 

 side view shows the *' coronse " well. Minneapolis, Minnesota, 

 U.S.A. Figs. 9a, h. 



Long. 70-78 fi= -00276-307 in.; lat. max. 52-58 /* = 

 •00205-228 in. ; lat. isthmi 13 /* = -0005 in. 



MiOBASTERiAS Agdh. (in part.) Mengh. 



10. M. furcata Ealfs (non Agdh.) nov. var. deeurta. A 

 strange and apparently abnormal form. Only two semi-cells seen, 

 of which one possessed a curious double lobelet. Water Town, 

 New York, U.S.A. 



Long, (semi-cell) 72 /i = -00283 in.; lat. 166 /x = -0065 in. ; 

 lat. isthmi 24 yti = "00094 in. Fig. 10. 



11. M. Crux-Melitensis (Ehr.) Ealfs nov. var. sujoerflua. In 

 this the superior side lobelets are trifid, end lobe with curved 

 points. Several specimens seen, having one or both segments as 

 figured. Near Bowness, Windermere. 



Long. 116/^ = -00457 in.; lat. 102 /* = -004in. ; lat. isthmi 

 17 /i= -00067 in. Fig. 11. , 



[Note. — I find that the American forms of this species are 

 large, with broad end lobes. They measure long. 145-152 fi = 

 •0057-599 in. ; lat. 118-130 fx, = -0046-51 in. ; lat. isthmi 23- 

 28 /Li = -0009- -0011 in. The Rev. F. Wolle, Amer. Desm. 

 p. Ill, t. XXXV. f 3, gives an abnormal form as his example of the 

 species, and says "diam. 100-125 //.." The form Mr. Wolle gives 

 is near that given by Ealfs, Br. Desm. t. ix. f 3 h, which is not 

 common, i. 3 a being the typical one. Ealfs, p. 74, notes the 

 dimensions of English specimens as long. 123 /j, = • 00485 in. ; lat. 

 115/^= -00452.] 



12. M. mamillata nov. sp. A very interesting and well- 

 marked form. Segments papilionaceous, five-lobed ; end lobe 

 broad ; its ends and those of the other lobes divided into palmate 

 shapes, with the points broadly rounded ; surface adorned with 

 mamilliform processes radially arranged ; provided with a process at 

 isthmus, the purpose of which is apparently (?) to strengthen the 

 segmental union. Only one specimen (semi-cell) seen. Seemingly 

 related to M. apiculata Ehr. Harvey Lake, U.S.A. Fig. 12. 



Long, (semi-cell) 114//,= -00449 in.; lat. base 198 /i = 

 - 0078 in. ; lat. isthmi 23 /x = • 0009 in. 



13. M. Americana Ehr. nov. var. spinosa. A small "com- 

 pressed " form. About one-eighth less in length and breadth than 

 the type. Central portion of segments smooth ; lobes ornamented 



