UNIO. 511 
a. Long. 114; alt. vert. 79, alee 7 5, diam. ? millim. Vertices 2 long. 
beef 126. = BOy 40 0G, © ag 40, ir : 
G4, E22 ss S65 TOs ad rr 
a 3, 122: “si She ys 763, ,, 37 
e 126; . 85, js 7s. ae BT = Pn 
a. ‘Pype: feos Philippi’s figure; -d. Specimens in the Berlin Museum; ¢. Villa’s U. lapidosus. Inside 
white in a, b, d, ¢; pale purple in c. 
Hab. N.E. Mexico: Rio Panuco, at Tampico !° (Dr. H. Wilckens, 1842, according to a 
label in the late Dunker’s collection). 
9 
», (figured). 
Cole Colin COldo Coles 
The type of U. lapidosus, sent to me by Villa himself about 1855, is labelled 
“Kuphrat. river.” I purposely omitted the species from my enumeration of the fresh- 
water shells of Western Asia, ‘ Vorderasiatische Conchylien,’ pp. 67, 68 (1874), on 
account of its being so very different from the other forms known from that region, 
but communicated it to Dr. Kobelt when he was working on the same subject in 1893. 
Villa’s shell now proves to be exactly like U. panucoensis; the locality quoted must 
therefore be erroneous. 
* 87. Unio tampicoensis. (Tab. XXXIII. figg. 1, 1a, 0.) 
Unio tampicoensis, Lea, Trans. Am. Phil. Soc. vi. p. 24, t. 7. fig. 18 (1836) *; Obs. Gen. Unio, ii. 
p. 24, t. 7. fig. 18°, and iii. p. 72°; Hanley, Cat. Rec. Bivalv. p. 188, t. 20. fig. 36*; Chenu, 
Illustr. Conch., Unio, t. 21. fig. 5°; Sowerby, in Reeve’s Conch. Icon. xvi., Unio, t. 57 
fig. 291°; Fisch. & Crosse, Miss. Scient. Mex., Moll. ii. p. 586”. 
Elliptically Eee with smooth, somewhat shining, greenish-brown periostracum ; ventral margin straight at 
the middle, well rounded before and behind; summits in 3-3 of the length. Inside white, at the posterior 
laminar teeth rose-coloured, in some specimens the whole inside rose or purple. Anterior teeth com- 
paratively small, moderately strong. 
a. Long. 112; alt. vert. 64, ale 66, diam. 42 millim. Vertices in ? long. 
b. 99 103 ; 99 62, ” 60, 99 ah 99 99 2 $9 
C. 9 973 3 99 65, ” 59, " 37s 9 99 3 
a. From Lea’s figure of the type’*; 6 and c. Specimens in the Berlin Museum; 6 certainly, ¢ probably, 
obtained from v. d. Busch. 
Hab. N.E. Mexico: Rio Tampico (Ronaldson1?); near Tampico (coll. Albers); Rio 
Moctezuma (Blanding °). 
FE. Mexico: Rio Medellin, ten miles south of Vera Cruz (Dr. Burrough |). 
Also occurs in the Rio Pecos, Texas (Lloyd). 
The two specimens of this Unio before me, one (0) from Albers’s, the other (¢) from 
Paetel’s collection (here figured), differ remarkably in the proportion of the length to 
the height, as will be seen from the measurements given, but they agree so well in all 
other respects that I cannot doubt their identity ; both are marked here and there with 
short linear desceriding impressions (see figure), which I do not find mentioned in any 
description. They have the inside white, with a rosy hue on the upperside of the 
laminar posterior teeth. : 
