156 MICROCERAMUS. 



shell from Tekanto. Strebel has figured a shell from Coban, 

 agreeing with those from Yucatan. 



2a. Var. arctispirus (Ancey). PL 25, figs. 5, 6. 



Similar to small specimens of concisus, except that the 

 umbilical chink is more reduced, almost obliterated. Length 

 of types 7-8, diam. 3 mm., whorls 9y 2 to 10. Other specimens 

 of the original lot measure 6 to 7.5 mm. long. 



Utilla Island, Honduras (Chas. T. Simpson). 



Macroceramus gossei var. arctispirus ANCEY, Ann. de Mala- 

 cologie, ii, p. 242 (1886). 



The figures represent specimens of the original lot received 

 from Simpson. It may possibly stand as an insular race 

 characterized by the shorter rima, but I can find no other 

 distinction from small individuals of concisus, which are 

 often equally conic. 



3. M. MEXICANUS (v. Martens). PL 26, figs. 25, 26, 27. 



" Relatively shorter and broader, length 8.5 to 9.5, diam. 

 of the last whorl 3 to 3.5 mm. ; 9y 2 to 9% whorls only. White 

 papillae at the suture small, scattered, and few in number. 

 Peristome of the aperture rather thin. Number of costulse 

 60 or more, according to Strebel ; some of them, however, are 

 so indistinct that it is very difficult to count them." (Mart.) 



Eastern Mexico: Orizaba (Berendt, Botteri, Hoge) ; Atoyac 

 (H. H. Smith) ; Arroyo grande, near Misantla (Salas). Cen- 

 tral Mexico: Sayula, State of Jalisco, one specimen not full 

 grown (Hoge). Northeastern Mexico: near Victoria, in a 

 canyon of the Sierra Madre, Tamaulipas; and Diente moun- 

 tain, near Monterey, Neuvo Leon (S. N. Rhoads). 



Macroceramus pontificus STREBEL, Beitrag Mex., etc., iv, 

 p. 89, pi. 5, f. 4:d (specimen from Orizaba). PILSBRY, Proc. 

 A. N. S. Phila., 1891, p. 316 (Orizaba). Not M. pontificus 

 Gld. Macroceramus concisus var. mexicanus MARTENS, Bio- 

 logia, p. 287, pi. 17, f. 2 (Dec., 1897). 



Von Marten's figure (fig. 25) and description are given. 

 A single specimen collected about 500 ft. above the town of 



