NO. 1205. SYNOPSIS OF THE NAIADES— SIMPSON. 595 



tNEPHRONAIAS RETICULATUS Simpson. 



* Ntphronaias reticulatus Simpson, Pr. Ac. N. Sci. Phila., 1900, p. 77, pi. ii, fig. 3. 

 Patook Eiver, Honduras. 



(Group of JSfephronaias scamnatus.) 



Shell elliptical to elongate, compressed, strongly sulcate, rather solid, 

 subbiangular behind; that of the female inflated at post-base; epider- 

 mis olive to brown, sometimes feebly rayed; beak sculpture delicate 

 and but slightly marked, consisting of faint, parallel ridges, which 

 show a tendency to fall into two rounded loops; hinge rather solid; 

 pseudocardinals stumpy, ragged, laterals straight; front part of the 

 shell solid and suddenly becoming thinner behind; nacre bluish, white, 

 salmon, or purple. 



Animal unknown. 



tNEPHRONAIAS SCAMNATUS Morelet. 



* Unio scamnatus Morelet, Test. Nov., No. 1, 1849, p. 30.— *Poey, Mem. Hist. 



Cuba, II, 1858, p. 417.— * Arango, Faun. Mai, Cuba, 1878, p. 144.— * B. H. 

 Wright, Check List, 1888.— *P^tel, Conch. Sam., Ill, 1890, p. 167. 



* Margaron {Unio) scamnatus Lea, Syn., 1852, p. 40; 1870, p. 35. 



* Unio gundlachi Sowerby, Conch. Icon., XVI, 1866, pi. XLVi, fig. 248. 



Cuba; Honduras'? 



tNEPHRONAIAS GUNDLACHI Dunker. 



*Unio gundlachi Dunker,' Mai. Blatt., V, 1858, p. 228.— * Arango, Faun.. Mai. 

 Cuba, 1878, p. 144.— *P^tel, Conch. Sam., Ill, 1890, p. 154. 



Cuba. 



NEPHRONAIAS iERUGINOSUS MoreleU 



* Unio airuginosus Morelet, Test. Noviss., I, 1849, p. 29. — * B. H. Wright, Check 



List, 1888.—* Fischer and Crosse, Miss. Sci., Pt. 7, II, 1894, p. 596, pi. lxii, 

 figs. 2, 2a, 2h. 



Eiver Michol, at Palenque, State of Chiapas, Mexico. 



' Lea and Poey regard this as the equivalent of N. scamnatus of Morelet, while 

 Arango believes it to be distinct. Unfortunately both species were described in 

 Latin and not figured, but Dunker states that his species is inflated posteriorly and 

 has a bluish nacre, and it is probable that he had before him a female shell when he 

 wrote the description, for one of the Cuban species, which I think is gundlachi, 

 has a bluish nacre, and the female shell is decidedly swollen at the post-basal region. 

 In another form, which I presume is N. scamnatus of Morelet, the nacre is rather 

 dark, the shell somewhat elongated, and that of the female does not greatly differ 

 from the male. 



^I am not positive that this species belongs here, but its form is like that of most 

 of the members of the genus, and Crosse and Fischer state that the beaks in their 

 specimen are entire and smooth. In several of the species of this genus the beak 

 sculpture is very faint, while in Unio it is almost always strong. These considerations 

 lead me to place the species here. 



