May 2, 1902.] 



SCIENCE. 



717 



colximella usually has two folds instead of the 

 three which is the prevailing state at Mont- 

 gomery. These differences also hold good with 

 the same species as found in the Yoxmg's 

 Bluff hed, which must be very nearly syn- 

 chronous with the Kimbrel bed, but the for- 

 mer is nevertheless sufficiently distinct in 

 horizon to have developed another characteris- 

 tic species of Lucina, occurring there very 

 abundantly. It is also very minute, though 

 a little larger than atotna and may be named 

 perminuta. 



This species is suborbicular, generally a lit- 

 tle longer than high, less inflated than atoma 

 and much thinner in substance, similarly in- 

 equilateral and more broadly rounded behind, 

 with the lunule much deeper and more evi- 

 dent and only slightly more than twice as long 

 as wide. The hinge is much thinner and the 

 lateral teeth are similarly placed, but much 

 weaker. The ventral edge is similarly crenu- 

 late and the external surface has much more 

 evident close-set and sublamelliform lines of 

 growth, the deep grooves of arrested develop- 

 ment, when present, being generally limited 

 to the ventral portions. The length of the 

 largest valve before me is 1.55 mm., the height 

 1.45 mm. 



It is probable that these two species, to- 

 gether with such forms as smithi and choc- 

 tavensis, should be considered generically dis- 

 tinct from Lucina. 



The bed at Montgomery contains myriads 

 of the very small pelecypod Alveinus minutus, 

 which may be considered one of its charac- 

 teristic species when comparing it with the 

 upper horizons, but no example of Eelliella 

 hcoitgeri Meyer — characteristic of the deposits 

 at Jackson, Miss. — or of the two minute Lu- 

 cinae, characterizing the overlying Kimbrel 

 and Young's Bluff beds, could be found. In 

 the Kimbrel deposit Alveinus minutus be- 

 comes extremely rare and one specimen of the 

 Kelliella, was obtained. Neither could be 

 found in the Young's Bluff outcrop, although 

 this was not so thoroughly examined. 



In venturing upon a suggestion of correla- 

 tion with the beds at Jackson, Miss., it seems 

 proper to consider the Montgomery outcrop 

 as virtually synchronous with the Dry Creek 



deposit, and the Kimbrel bed as well above the 

 Moody's Branch beds. The Young's Bluff bed 

 is still higher, but neither seems to have devel- 

 oped any of the purely Ked Bluff species, al- 

 though lithologically they both appear to be 

 somewhat similar to that well-known deposit 

 in Mississippi. As these greenish-black clays 

 are however similar to those which also char- 

 acterize so much of the Lower Claiborne in 

 Louisiana, very little can be inferred from 

 such resemblances. In fact, lithological char- 

 acters stand for very little in the strata of 

 the southern Tertiary, except in a few in- 

 stances and the paleontological are the only 

 ones that can generally be depended upon. 

 Thos. L. Casey. 

 St. Louis, Missouri, 

 March 11, 1902. 



THE NOMENCLATURE OF THE MONOPHLEBINE 

 COCCIDAE. 



Working over the Monophlebinse for Wyts- 

 man's 'Genera Insectorum,' I find myself able 

 to recognize six genera out of about fifteen 

 which have been proposed. These are Mono- 

 ■phlehus, Stigmacoccus, Lophococcus, Palceo- 

 coccus, Walheriana and Icerya. At present I 

 am unable to separate Crypiicerya from Paloeo- 

 coccus and the latter is connected by lately dis- 

 covered forms with Walkeriana, so that it be- 

 comes difficult to indicate sharp generic limits. 

 These insects are very widely distributed and 

 ancient forms, going back at least to the Ter- 

 tiary, one species occurring fossil at Florissant. 



Mr. Newstead, in describing Walkeriana per- 

 tinax (P. Z. S., 1900, p. 948), says he at one 

 time 'thought the insect might form the type 

 of a new genus under the name Aspidoproctus,' 

 but has decided for the present to leave it in 

 Walkeriana. Now this creature forms at least 

 a good section or subgenus for which we need a 

 name. I am taking up Aspidoproctus, as of 

 Newstead, but am a little uncertain whether I 

 have the right to do it. I should like to have 

 the opinion of other naturalists, whether a 

 name introduced as cited is to be regarded as 

 published. Gymnococcus Douglas was intro- 

 duced in the same way and is now current. 



Some other new sections have been found 

 necessary. Mimosicerya, with 9-jointed female 



