﻿268 NI-I'IIKONAIAS 



cardinals with a smaller one between theni and two remote 

 laterals, right valve with one strong, ragged pseudocardinal 

 and sometimes a vestigial one above it, with one small lat- 

 eral ; beak cavities shallow with a large number of dorsal 

 scars extending forward under the teeth ; nuiscle scars well 

 imi)ressed ; pallial line well marked, sometimes crossed by 

 radiating furrows ; nacre bluish-white, white or yellow to 

 bright orange, in one or two shells purplish. 



I<ength 70. height 38. diam. 24 mm. 



Length 75, height 41, diam. 25 mm. 



Rio Copan, Guatemala (type) : Honduras, various localities 

 (Lea collection). 

 Unio tehuantepecensis var. copanensis von Martens, Biol. 



Cent. Am., Moll., 1900, p. 502, pi. xxxvi, fig. 6, 6a. 



A considerable number of shells of this form, part of them 

 from the type locality from von Ihering are in the National 

 Museum collection, others are in the Lea collection from Hon- 

 duras labeled scamnatus. This is a stronger, more rude, more 

 arcuate shell than U. tehuantepecensis and much more decid- 

 edly biangulate behind and I have no hesitation in considering 

 it worthv of specific rank. The Museum shells all agree very 

 well with von Martens' figures and descri]:)tion, but show con- 

 siderable of variation. All have the nacre thickened in front. 

 I cannot refer any of the shells I have seen from Cuba to 

 this species. One young specimen in the National Museum 

 is slightlv inflated in the post-basal region and may be a female 



Grouj) of Neplironaias reticulata. 



Shell evenly elliptical, slightly biangulate behind, solid and 

 inflated ; surface covered with fine, concentric ridges and hav- 

 ing delicate radiating furrows, which cut the sulcations and 

 form them into loops. 



Nepmronaias reticulata Simpson. 



Shell evenlv long elliptical, subinflated, rather solid, with a 

 low, somewhat double posterior ridge, which ends in a scarcely 

 perceptible biangulation 1)cliind ; beaks but slightly elevated. 



