MEXITERPES SABINUS , NEW GENUS AND NEW 
SPECIES, A MEXICAN TROGLOBITE 
(DIPLOPODA: TRICHOPETALIDAE) * 
By Nell B. Causey 
University of Arkansas, Fayetteville, Arkansas 
This troglobitic milliped is of unusual interest because it is the 
type of a new genus and the first Mexican record of the family Tri- 
chopetalidae, which previously has been known from Nova Scotia to 
Louisiana, Oklahoma, and Colorado. If the genus has undergone 
speciation as related genera have, then additional species and sub- 
species will be found in other Mexican caves. Other millipeds from 
Mexican caves have been described by R. V. Chamberlin (1942). 
I am indebted to the members of the Texas Speleological Survey 
for the specimen from which this species was described. 
Genus Mexiterpes, new 
Type-species : M. sabinus, n. sp. Monobasic. 
Diagnosis. Depigmented, eyeless, medium-sized trichopetalids of 
30 body segments that are nearest Scoterpes. Characterized by the 
gonopods and by the unmodified condition of all pregonopodal legs. 
Coxa of anterior gonopods bears one short branch on its distal mar- 
gin; telopodite is thick and short as in Scoterpes , but is more complex, 
seems to lack a plumose branch, and has a short, ectal, setose branch. 
Posterior gonopods are short, slender, and consist of 4 articles ; article 
1 is coalesced with its homologue in midline, and there is no partition 
between them; all other articles are separated by partitions; a gland 
opening is on article 1 at base of telopodite; article 2 is elongated as 
is usual in the family; combined length of articles 3 and 4, which 
are not inflated, is a little less than length of article 2. 
Mexiterpes sabinus, new species 
Figures 1-3 
Type locality. Mexico: San Luis Potosi : Sotano del Arroyo, which 
is near village of Los Sabinos and 8 miles north of Valles; 1 speci- 
men was collected on silt in Big Room 3000 feet from entrance 
after intensive search 24 Nov. 1962 by James R. Reddell. 
Deposition. Male holotype is in Museum of Comparative Zoology. 
Posterior gonopods are mounted on a slide ; anterior gonopods are in a 
microvial. 
* Manuscript received by the editor May 8, 1963. 
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