1905.] NATURAL SCIENCES OF PHILADELPHIA. 221 
Hondo river, two miles north of Hondo, Medina county, Texas (figs. 
10-15). The shells are much smaller than in western Texas, usually 
11 to 12 mm. long, and the diameter is generally less than4 mm. A 
large proportion of the shells have ‘overhanging’ upper whorls. 
They were picked out of river-débris, and probably came from the hill 
country some miles farther north. The measurements of fifty adult 
shells, all the perfect ones I found, follow: 
Ree ha) dies wiser 1g were) myo.) ge) V7 1g 
Diam. BiG Ndi LOL R A LB BOI OR. G14 os lie 
Bedside 14 18. 18h 12 8) 128 19.5 138 
tiene, nis 420 32° Tha aa 12 
Diam. PN SN haat VE Bae | alae Ca a es 4 
Mice tan Wie tee |e ae oe) 198" Ta” | 19: 
Poste ie oe ihe.) Th Tie VR iid d) 18 
Diam. 4 4 Bo) SO) Bae, ana OF ah eA 3.8 
Wioder 125 tae ioe 1an) Oe \ or ao. 2 fee 
Peete LEA MM ety Neots te, OMA, 61 
Diam. oWete: its 2 ae 4 NOMA NA gee O38 
Piherlehied2i eet de wee? dag sda $e yey) 
Pededuy vida G05 dh “10S 107° 107% 40." 10" ~~ ‘10 
Diam. SOM ZG TS 1G A Pera a Psa ees 
Fiona! Hel So ME ds te TR) Aes. cas 
Length 10 9:9; |) 9.& | 93°) 8:5 mm: 
Diam. BO SiG (8:3. 4,8) 8.9)" 
Whorls 114 11 114 103 10 
The lengths give the following curve, which, although of no great 
value on account of the small number of variates, is given for what it 
is worth. 
Genus MICROCERAMUS Pils. and Van. 
Nautilus, XI, p. 107; Proc. Acad. Nat. Sci. Phila., 1898, p. 281; Manual of 
Conchology, XVI, p. 151. 
