338 MEXICAN BOUNDARY SHELLS—DALL. volxix. 



carpenteriioia, Bland, bt'longs to ii different prroup, Newcomb's name 

 may jiroperly stand, even if Ave admit tbe i)rineiple propounded by 

 Crosse and Fischer to the effect that two species of one genus can not 

 be named for the same person, a claim which rests upon no established 

 rule, and is in fact in conflict with usagre. 



Two forms have been distributed or are found in collections under the 

 name of H. carpenieri, Newcomb. Unfortunately the original type of 

 Dr. Newcomb, Avliich Avas a bleached shell obtained from Frick (whose 

 localities are known to be often suspicious) Avith the erroneous locality, 

 "Tulare Valley," is no longer to be found in his collection, the doctor 

 having jx'rhaps replaced it by Avhat he considered better specimens of 

 the same species. The exact measurements of his original do not agree 

 with those of any si:»ecimen received from Dr. Newcomb or otherwise 

 under the name carpenteri. It is probable that the printed height of 

 the shell (1G.5 mm.) is a misi^rint or a mismeasurement for 14.5 mm. 

 Apart from this we learn from the diagnosis that the type was dis- 

 tinctly spirally striated and had 5| whorls. Now, one of the forms 

 circulated under the name carpenteri has very distinct striation and 

 the right number of whorls and diameter, and comes from the vicinity 

 of San Diego, California, and especially from the Coronado Islands 

 which are near San Diego off the coast. It is this which Mr. W. G. 

 Binney received from Dr. ISTewcomb as //. catpeitteri and has regarded 

 as entitled to the name. In this A'iew I agree, but suspect the shell to 

 be a local race of H. trasJcii, Newcomb, which is somewhat more elevated 

 and with fainter spiral stria'. The other shell, Avhich has T>een known 

 as carpenteri^ comes from Trinidad, Lower California, and near Mazat- 

 lan. State of Sinaloa, on the Mexican mainland, Avhere it Avas collected 

 by Gabb. It has only 4 to 5J whorls and is paler, with a thinner epi- 

 dermis and few traces of striation. It is probably a distinct species. 



Another species Avhicli has been contested is H. loJirii, Gabb, which 

 is a depressed shell with a curious oA'ately rounded, Avidely expanded 

 peristome, behind Avhicli the Avhorl is smaller though not abrui)tly con- 

 stricted. One of Gabb's types has a niaxinuim diameter of 22, a mini- 

 mum diameter of 1G.5, and a height of 10 mm. 



The surface of the spire is almost flat, the perii)hery is formed by an 

 almost angular shoulder high up on the Avhorl, and the umbilicus is 

 scalar, rcA'Caling the Avhorls to the apex. 



Through the courtesy of Prof. G. D. Harris, of Cornell University, 

 and the authorities of the University, I have had an opportunity of 

 comparing with typical specimens of H. JoJirii, receiA^ed from Gabl>, 

 the original types of H. roirelli, Newcomb, i)reserved in the Newcomb 

 collection, now the i)roperty of the university. Gabb's si)ecies have 

 very generally been referred to JL roirelU as a synonym, and they are 

 very closelj' related. One of Dr. Newcomb's specimens, and perhaps 

 two of them, belong to another species, 77. maf/dalenensis, Stearns, but 

 the more perfect ones upon which his description Avas founded are closely 



