UROCOPTIS, S. G. GONGYLOSTOMA. 283 



known. It is probably related to crispula, coronadoi and 

 their allies. 



U. DENTICULATA (Pfeiffer). Vol. XVI, PL 13, figs. 12, 13. 



Shell very slightly rimate, subulate, not truncate, thin, 

 the surface undulated with obtusely projecting arcuate lines ; 

 pale corneous, variegated with whitish; spire long, the apex 

 rather acute; suture closely denticulate with white. Whorls 

 19, rather flat, the last rib-striate in front ; base carinate ; not 

 built forward. Aperture subcircular, the peristome ex- 

 panded, somewhat interrupted above. Length 23, diam. 3.66, 

 aperture 3.75 mm. long (Pfr.). 



Mexico (Cuming Coll). 



Cylindrella denticulata PFR V Monogr., iii, p. 580 (1853) ; 

 Conchyl. Cab., p. 65, pi. 7, f. 14, 15. SOWERBY in Conch. 

 Icon., xx, pi. 3, f. 22. Macroceramus denticulatus Pfr., 

 FISCHER & CROSSE, Miss. Scient. Mex., Moll., i, p. 424. MAR- 

 TENS, Biologia Centr. Amer., Moll., p. 289. 



Prof, von Martens with good reason doubts the habitat 

 assigned to this species on the perilous authority of a Cumin- 

 gian label. The incomplete peristome and entire apex sug- 

 gest such forms of Tomelasmus as U. acus or irrorata. Similar 

 sutural papillae occur in U. hidalgoi and various other Cuban 

 species; but until the interior is examined no estimate of its 

 affinities can be made. It is not likely to be a Microceramus. 



U. MULTISPIRALIS (Sowerby). Vol. XVI, PL 11, fig. 82. 



' * Shell very long, narrow, fawn ; whorls 24, rather straight ; 

 last loosened some length. Aperture distant, subovate " 

 (Sowb., C. Icon., xx, pi. 9, f. 79; 1875). 



Habitat unknown. A shell resembling U. lateralis is indi- 

 cated. Messrs. Sowerby and Fulton inform me that it is not 

 in their collection, and Mr. Edgar A. Smith states that it 

 cannot be found in the collection of the British Museum. 



The two genera now following, Spirostemma and Anoma, 

 agree with Urocoptis in (1) the general structure of the shell, 

 (2) the V-shaped rows of teeth, of which the centrals are 



