112 K. J. Bush — Marine Gastropods referred to 



"Shell orbicular, convex, conoid, smooth, shining, white, carinated; 

 spire conic with obtuse apex, of five distinct, convex whorls ; um- 

 bilicus small, smooth ; aperture oval. Diara. 3'"™ ; alt. 2'""." 



Hist. L'ile de Cuba, Moll., ii, p. 67 ; atlas, pi. xix, figs. 25-27, 1853. 



Prof. Murch constituted the above as a subgenus under Archi- 

 tectonica Bolten, 1798 = Solarium Lamarck, 1799. 



Prof. Fischer placed it, with a mark of doubt, in the same relation ; 

 but Dr. Dall (Bull. M. C. Z., xviii, pp. 273, 392, 1889) suggested that 

 it might prove to be more closely related to Adeorhis (i. e. Circulus) 

 or to a Vitrinella (?) like V. midticarinata, which he described as 

 having the epidermis produced into a fringe on the secondary carinas, 

 above and below the peripheral one. The hairy epidermis would 

 exclude this species from Vitrinella, p. 105. 



Trachysma G. 0. Sars, 1878 (Jeffrey's MSS.) Type, T. delicatum (Philippi). Italian 

 Tertiary and Lofoten Is., 200-300 fathoms. 



" Shell globular, rather thin, similar to a Cyclostrema (i, e. Lisso- 

 spira) but more delicate, aperture open or spreading out, peritreme 

 simple, with a very thin, distinct edge." 



Type, T. delicatum (Philippi) G. O. Sars. 



" Shell thin, semipellucid, white, globular with short, little elevated 

 spire, consisting of three and one-half convex whorls, the last large, 

 evenly convex, the base not flattened. Suture deep. Aperture large, 

 round-ovate with the outer-lip evenly arched and the columella 

 slightly incurved. Umbilicus deep, not defined from the base (i. e. 

 with rounded walls). Upper part scarcely shining, to the naked 

 eye smooth, but seen under the microscope very finely sculptured, 

 with numerous longitudinal and interrupted spiral lines. Diam. 

 1-1™°' ; alt. 1™""." 



Var. expansa G. O. Sars. 



" Shell more dilated, the last whorl wide and very large, the base 

 slightly flattened, the aperture widely open and expanded in an 

 unusual manner, the lip oblique and irregularly curved. Diam. basis 

 1-4'"'"; alt. i-2">'"." Moll. Reg. Arct. Norv., p. 211, pi. 22, figs. 17- 

 \M, 1878. 



Although Mr. Jeffreys seems to have proposed the name Trachysma 

 for a species from Lofoten Is, which he identified as the delicatum 

 of Philippi, I fail to find any reference to such a genus or species in 

 any of his later reports on the " Porcupine Expedition." Therefore 

 G. O. Sars should stand as the authority for the genus. 



He placed it with the Solariidae, but his figures {\%a-d) of the 



