PROCEEDINGS OF THE ACADEMY OF NATURAL SCIENCES OF PHILADELPHIA. 1896. COMMITTEE ON PUBLICATION: Thomas Meehan, Charles E. Smith, Edward J. Nolan, M. D., George H. Horn, M. D., Henry Skinner, M. D. Editor: EDWARD J. NOLAN, M. D. PHILADELPHIA : ACADEMY OF NATURAL SCIENCES, LOGAN SQUARE. 1897. Academy of Natural Sciences of Philadelphia, February 4, 1897. I hereby certify that printed copies of the Proceedings of the- Academy for 1896 have been presented to the meetings of the Academy as follows : — Pages 9 to 24 ' 25 to 104 ' 105 to 168 ' 169 to 200 ' 201 to 216 ' 217 to 264 ' • 265 to 280 ' 281 to 312 ' 313 to 376 ' 377 to 392 ' 393 to 456 ' 457 to 466 ' 467 to 482 " 483 to 546 ' 547 to 562 " 563 to 594 February 25, 1896. March 17, 1896. April 14, 1896. . April 21, 1896. May 12, 1896. . May 26, 1896. June 16, 1896. . July 21, 1896. . August 4, 1896. . August 11, 1896. . September 15, 1896. . September 22, 1896. . October 27, 1896. . December 8, 1896. . December 15, 1896. . February 2, 1897. EDWARD J. NOLAN, Recording Secretary THE EDWARDS & DOCKER CO , PRINTERS, PHILA LIST OF CONTRIBUTORS. With reference to the several articles contributed by each. For Verbal Communications see General Index. Allen, Harrison, M. D. A biographical sketch of John Adams Ryder 222 Note on a uniform plan of describing the human skull . . 170 Brown, Amos P. The crystallization of Molybdenite 210 Cockerell, T. D. A. The Bees of the Genus Perdita F. Smith . 25 Cook, O. F. Summary of the new Liberian Polydesmoidea . . 257 Cope, Edward D. The Mesenteries of the Sauria 308 New and little-known Mammalia from the Port Kennedy Bone Deposit 378 On the Hemipenes of the Sauria 461 Dall, WilHam Healey. Insular landshell faunas, especially as illustrated by the data obtained by Dr. G. Baur in the Galapagos Islands (Plates XV, XVI, XVII) 395 Dolley, Charles S., M. D. The Planktonokrit, a centrifugal ap- paratvis for the volumetric estimation of the food-supply of oysters and other aquatic animals 276 Fox, William J. Contributions to a knowledge of the Hymen- optera of Brazil. No. 1, Scoliidae 292 The Hymenoptera collected by A. Donaldson Smith in Northeastern Africa 547 Harris, Gilbert D. New and interesting Eocene Mollusca from the Gulf States (Plates XVIII, XIX, XX, XXI, XXII, XXIII) 470 Henry, Fredk. P., M. D. Remarks on Filaria 271 Keller, Ida A. The coloring matter of the Aril of Celastrus scandens 212 Pilsbry, Henry A. New species of the Helicoid Genus Polygyra (Plates II and III) 15 Description of new species of Mollusks 21 A remarkable Central American Melanian 269 / f 3 3 New species of fresh water Mollusks from South America (Plates XXVI and XXVII) 561 Geology of the mussel-bearing clays of Fish-house, New Jersey 567 Pilsbry, Henry A. and Samuel N. Ehoads. Contributions to the Zoology of Tennessee. No. 4, Mollusks 487 Pilsbry, Henry A. and E. G. Vanatta. Catalogue of the species of Cerion, with descriptions of new forms (Plate XI) . . 315 Revision of the North American Slugs : Ariolimax and Aphallarion (Plates XII, XIII, XIV) 350 Rhoads, Samuel N. Contributions to the Zoology of Tennessee. No. 3, Mammals 175 Synopsis of the Polar Hares of North America (Plates VI, VII, VIII, IX, X) 351 Mammals collected by Dr. A. Donaldson Smith during his expedition to Lake Rudolf, Africa (Plate XXV) '. . . . 517 Shufeldt, R. W., M. D. Fossil birds and Mammals from Grotto Pietro Tamponi and Grive-St. Alban (Plate XXIV) . . 507 Stone, Witmer. The molting of birds, with special reference to the plumage of the smaller land birds of Eastern North America (Plates IV and V) 108 PROCEEDINGS OF THE ACADEMY OF NATURAL SCIENCES OF PHILADELPHIA. 1896. January 7. The President, Samuel G. Dixon, M. D., in the Chair. One hundred and forty-three persons present. The deaths of R. B. Haines and A. C. Gorgas, M. D., members, were announced. The Council reported that the following Standing Committees have been appointed to serve during the current year : — On Library. — Arthur Erwin Brown, Harrison Allen, M. D., Henry C. Chapman, M. D., Chas. P. Perot and Henry A. Pilsbry. On Publications. — Thomas Meehan, Charles E. Smith, George H. Horn, M. D., Edward J. Nolan, M. D. and Henry Skinner, M. D. On Instruction and Lectures. — Harrison Allen, M. D., Benjamin Sharp, M. D., George Vaux, Jr., C. Newlin Peirce, D. D. S. and Uselma C. Smith. Standing Committee of Council on By-Laws. — Isaac J. Wistar, Theodore D. Rand, William Sellers and Benjamin Tilgh- man . 2 10 PROCEEDINGS OF THE ACADEMY OF [1896. The following minute was unanimously adopted : In view of the fact that General Isaac J. Wistar has served four consecutive years, the limit defined by the By-Laws, as Presi- dent of the Academy of Natural Sciences of Philadelphia, his fellow members desire to indicate their esteem and affection by a cordial endorsement of the minute of recognition adopted by the Council and to express the hope that the Academy may long profit by the clearness of judgment, the knowledge of affairs and the courtesy of personal intercourse which have been the characteristics of his administration. Dr. Benjamin Sharp made a second communication on his ethnological studies in Alaska and Siberia. (No abstract). January 14. The President, Samuel G. Dixon, M. D., in the Chair. Thirty-four persons present. The death of Samuel G. Lewis, a member, was announced. A paper entitled " New Species of the Helicoid Genus Polygyra," by H. A. Pilsbry, was presented for publication. Pleurotomaria erotaloides Morton in the New Jersey Cretaceous. — Mr. H. a. Pilsbry exhibited a fossil Pleurotomaria from Mullica Hill, New Jersey, found by Henry L. Balderston when on a excur- sion of the geological class of Westtown School, and submitted to the speaker by Lewis Woolman. ^ The specimen is an internal cast and has lost the earlier whorls. Enough remains, however, to distinguish it as a strongly marked species, apparently identical with Cirrus erotaloides Morton\ des- cribed from Erie, Alabama. The species has not been noticed since its original publication in 1834, and as Morton's description is very brief (less than three lines long) and involves a grave inaccuracy, and his figure is decidedly uncharacteristic, a more detailed description of the spec- imen discovered by Mr. Balderston is here given, followed by notes on Morton's type specimen. It may be described as follows : Pleurotomaria crotaloides Morton. (Plate I). Shell (cast) rather discoidal, the spire low-conic, base flattened and very broadly umbilicated. Whorls slowly increasing, very convex, separated by deep sutures ; the last whorl strongly convex on the upper surface, thence sloping outward to the periphery, which is quite convex again, and near the base of the whorl. Base dis- * Synopsis of the Organic Remains of the Cretaceous Group of the U. S. p. 49, pi. 19, fig. 5. 1896.] NATURAL SCIENCES OF PHILADELPHIA. 11 tiuctly flattened, though convex. Umbilicus somewhat exceeding one-third the total diameter, broad, deep and perspective, the sutures within it strongly impressed. Diameter 7 cm. ; width of last whorl at aperture (measured below) 26 mm.; alt. of same about 19 mm. The surface of the cast is smooth, not showing the impression of the anal fasciole. The sinus was probably short, at least in compar- ison with the large recent species ; but as the latter third of the specimen is largely concealed by a hard arenaceous matrix, no im- pression of the anal sinus can be made out. The unremoved matrix shows clear impressions (external moulds) of the characteristic Lower and Middle Marl bed species Plicatula urticosa Mort. and Ostrcea larva Lam. In Pleurotomaria perlata Conr., the periphery is more strongly keeled and the umbilicus narrower than in this species. In Pleuro- trema solariformis Whitf. the whorls are flatter both outside and within the umbilicus, and the slit is said to be bridged at intervals, though this last feature is excessively obscure if present in the type specimen. The specimen described above is the property of Henry L. Bal- derston and has for the present been deposited in the museum of the Academy. The type of Cirrus crotaloides Morton is a much smaller shell, alt. 18, diara. 39 mm. It is an internal cast of whitish calcareous material ("rotten limestone"). The last whorl has been broken above near the aperture, and the whorls of spire are slightly distorted on one side by pressure, and have lost considerable material by ero- sion. The umbilicus is filled to its verge with a calcareo-arenaceous matrix, harder than the cast itself, and a narrowly conic protuber- ance of the same material projects over the apex. This has been mistaken by Morton for the true spire, which accounts for his words " the two first whorls [sic] suddenly produced." In reality the true apex of the shell is concealed by this bit of hard matrix, about three whorls being visible. The contour of the last whorl is practically identical with that shown in the middle figure of the plate illustrat- ing the Mullica Hill specimen. No impression of the anal sinus or fasciole is visible on the cast. Erie, the locality Avhere Conrad collected the type of crotaloides, is on the Black Warrior River, in the Selma Chalk or " Rotten Limestone " member of the Alabama Cretaceous. January 21. The President, Samuel G. Dixon, M. D., in the Chair. Fifty-two persons present. Papers under the following titles were presented for publication : — 12 PROCEEDINGS OF THE ACADEMY OF [1896. " Descriptions of New Species of Mollusks," by H. A. Pilsbry. "The Molting of Birds with special reference to the Plumage of the Smaller Birds of Eastern North America," by Witmer Stone. The deaths of George Edward Dobson and Don Antonio del Castillo, correspondents, were announced. January 28. The President, Samuel G. Dixon, M. D., in the Chair. Thirteen persons present. A paper entitled "Contributions to the Zoology of Tennessee, No. 3, Mammals," by Samuel N. Rhoads, was presented for publica- tion. A resolution having been adopted at the preceding meeting pro- viding for an inquiry as to the best method of exterminating the Tussock JSIoth, Orgyia leucostigma, with which the city squares and trees are infested, the subject was referred to the Entomological Section, a committee of which reported as follows : — AVe would recommend for the destruction and extermination of the Tussock Moth, Orgyia leucostigma, that as soon as possible all the egg masses be hand-picked from the trees and destroyed. To be effective, this must be done before the first day of April. The trunk of each tree should be encircled about five feet from the ground by a band of " Raupenleim " or Dendroline, four inches wide and a quarter of an inch thick ; this band should be renewed once a month during the summer season. All eggs, cocoons and caterpillars segregated below the band should be gathered and burned ; or they may be killed by steam or by the flame apparatus used by house painters. The committee is confident that the above method, if properly carried out, will exterminate the species in a given locality in two or three seasons, and put them under control the first summer. The committee has never seen this method properly carried out. Failure in the past has been due to the integrity of the band not being maintained and to the fact that a few segregated insects and eggs were simply brushed to the ground where the eggs hatched and the caterpillars reascended the trees. The life-history of the species will show why the methods described must prove successful, and we append an account of the transformations of this defoliator of our shade trees : — " These caterpillars are first noticed on the trees in May, quite small, feeding on the leaves, and somewhat indifferently on either 1896.] NATURAL SCIENCES OF PHILADELPHIA. 13 the upper or under side. When suddenly disturbed they drop from their perch, suspending themselves by a silken thread, which is at- tached to the leaf from which they started. They retain this habit until they are nearly full-grown, which occurs about the middle or toward the end of June. They then begin to wander, leaving the trees on which they have fed, often crawling to others, and some- times travelling several hundred feet from the starting point before deciding to pupate. When they are ready for the change they spin their whitish cocoon in any convenient place ; in the angles of wooden tree boxes, under the rails of fences, in the interstices of bark of the trees themselves, and in fact in any likely or unlikely place except a perfectly Hat, smooth surface. The caterpillar has a very small supply of silk only, and to eke this out uses its own hair which it breaks off close to the body and forms the cocoon by a sort of felting process, the silk serving to give form and holding together the hair. In the cocoon the larvse change to dirty yellowish or gray pupre, the male much smaller than the female and showing rudiments of the future wings, while the female is nearly double the size and is grub or slug-like in form. Less than two weeks there- after the final change takes place and the adults emerge — the sexes strikingly dissimilar in appearance. The male has two pairs of broad dusty gray wings, the anteriors crossed by narrow black lines, and with a more or less prominent white spot toward the lower outer angle. The feelers or antennae are broadly feathered and prominent, while the fore-legs are plumed and tufted, stretched straight forwaixl when the moth is at rest, so as to be the most conspicuous feature of the insect. The female, on the other hand, is entirely without wings, and somewhat slug-like, consisting princi- pally of an abdomen, which is enormously distended with eggs. AVhen she emerges from the pupa, she crawls upon the cocoon to which she clings, almost motionless for the balance of her life. Egg-laving begins soon after impregnation, the eggs being laid upon the old cocoon and covered with a frothy mass, which soon be- comes bard and brittle and is snowy-white. As the eggs are laid, the female diminishes in size, eventually shrinking almost into nothingness and finally drops off dead. Neither male nor female takes food in this stage, their adult existence is devoted merely to reproduction. From the egg-masses above described, a second brood of larvre hatches in July and the same life cycle is repeated, the adults of this brood appearing in September. The eggs laid at this time of life remain unhatched during the winter."^ It will be readily seen from this life history that the females being wingless the species can only be distributed by the crawling propensity of the caterpillar ; this, together with the fact that the eggs are all laid in a mass, gives the key to the method of destroy- ing them. Each egg-mass destroyed means the death of about three ^Eept. Ent. Dep., N. J. Agric. Col. Exp. Station, 1894. 14 PROCEEDINGS OF THE ACADEMY OF [1896. hundred and fifty caterpillars. It takes a little experience to find the egg-masses in the winter, and very few would escape, to hatch out, if they were intelligently sought for. It must be remembered that they go through their metamorphoses almost in an automatic way and human endeavor to check them must proceed after the same plan, an old Latin phrase not being forgotten: ' Nihil sine labore.' Generally no attention is paid to pests of this kind until they become so bad as to attract the attention of the general public. Respectfully submitted by Wm 7 F V ' I (^(^^^^^^ii^^ of the Ento77iological Section. The following were elected members: Henry Trimble, Charles E. Hite, C. Howard Colket, George de Schweinitz, M. D., James C. Corry, D. Calvin Mensch, Edward Gideon, I. Norris de Haven, Ruth Clement, M. D., and Sarah Y. Stevenson. The following were ordered to be printed : — 1896.] NATURAL SCIENCES OF PHILADELPHIA. 15 NEW SPECIES OF THE HELICOID GENUS POLYGYRA. BY HENRY A. PILSBRY. At the request of Mr. John Ponsonby of London, the determina- tion of a series of Polygyras of unknown or doubtful specific identity, from his collection, was undertaken by the writer. In the course of this work, the Mexican species of the genus were reviewed, the identification of the Academy's material verified, and several specific forms, hitherto nameless or under incorrect names, were studied. The following communication relates to species of that character- istic " Lower Sonoran " group of Polygyra, of which P. plagioglossa and P. ventrosula represent approximately the extremes in the cycle of form changes. The types of P. latispira, matermontana and eiighjpta' are in the collection of the Academy. The types of P. Ponsonbyi are in the same collection and that of Mr. Ponsonby ; and the type of P. albicostulata is in Ponsonby's collection. These five species, with P. Mearnsii and P. chiricahuana Dall (Proc. U. S. Nat. Mus., 1895), and P. solidens and P. triangularis Mabille (Bull. Soc. Philomath, de Paris, 1895) complete the list of Polygyras given in the Guide to the Study of Helices, pp. 73, 74. P. latispira n. sp. PI. Ill, figs. 13, 14, 15, 16. Shell depressed, with convex spire, rounded but noticeably shoul- dered periphery and convex base; unibilicated, the umbilicus within deep and cylindrical, about "8 mm. diam., at the last whorl rapidly enlarging, 2"3 mm. diam., or contained about five times in the diameter of the shell, conspicuously grooved inside. Surface very closely and regularly rib-striate, moderately shining. Light yellow or buff" in color. Whorls 52, closely coiled, slowly widening, rather convex, having an oblique impression behind the outer, and an excavation behind the basal lip. Suture well impressed, descend- ing only a trifle at the aperture. Aperture quite oblique, roundly lunate, the lip forming two-thirds of a circle, rather narrowly reflexed ; outer lip bearing an inwardly projecting pointed tooth ; basal lip with a slightly keeled face along 16 PROCEEDINGS OF THE ACADEMY OF [1896. its outer half, the inner part bearing a rather long, low, callous tooth with the summit a trifle flanged outwardly. Deep within the aperture a lobe-like tooth may be seen on the columella. Parietal tooth small, V-shaped, the outer ridge of the V extremely short. Alt. 6, greater diam. lit, lesser IO2 mm. The specimens serving as types were collected some years ago (about 1880) by Dr. Horatio C. Wood in western Texas, either in the " Great Bend " of the Rio Grande or near El Paso, exact locality not noted. The species is somewhat allied to P. plag log lossa, having about the same general contour and agreeing in the proportions of the parietal lamella; but the armature of the basal lip is conspicuously different, and there is a deep-seated lamella on the columella, such as well developed examples of P. Mooreana show, but apparently united by a low ridge with the inner end of the basal tooth. This lamella corresponds to the groove within the umbilicus, and is not visible in the drawings. P. matermontana n. sp. PI. Ill, figs. 10, 11, 12. Shell depressed, with low, convex spire, rounded periphery and convex base ; umbilicated, the axial perforation small and deep, at the last whorl rapidly enlarging to about one-fifth the diameter of shell. Surface shining, faintly wrinkled by growth-lines and show- ing under the lens superficial close spirals in some places; light horn colored. Whorls 5i, quite convex, the inner slowly increas- ing, narrow, the last decidedly wider, notably convex above, with the periphery above the middle ; deeply and narrowly constricted behind the lip. Suture well impressed, abruptly deflexed in front. Aperture quite oblique, rounded oval, the lip forming over two- thirds of the circumference ; outer lip broadly expanded, flaring, bearing a concave lamella with a denticle at the lower end on its inner edge ; basal lip reflexed, with a compressed, slightly entering tooth. Parietal callus a translucent film, bearing a V-shaped lam- ella not connected with the peristome, the outer branch of the V very short. Alt. 5"2, greater diam. 9*5, lesser 8 mm. Colima, Sierra Madre Mts., Mexico. Besides the types from above locality, there is one specimen in the collection of the Academy labelled " ^Mexico " differing in size, alt. 6*1, greater diam. 11 mm., and having 6 whorls. It agrees in all other characters and is doubtless the same specifically. Two other specimens labelled "Texas" are altogether like the types. 1896.] NATURAL SCIENCES OF PHILADELPHIA. 17 P. matermontana is like texasiana in the notch between the two lip-teeth, but the outer tooth is a more pronounced and shorter lamella, the parietal " V " is less developed, and the upper surface is not costalate. The parietal lamella is much alike in matermon- tana and laUsjiira, the outer branch being much less developed than in Ixichardsoni, veidrosula or bicru7-is. The umbilicus is like that of latispira, being slightly more ample than in texasiana, and with the central well, or perforation decidedly larger. This species and the three following have nearly the same form of aperture teeth and are very similar to other species group- ing immediately around P. ventrosula in this respect. The compar- ative width of umbilicus, the sculpture, and to a less extent, the contour, differ in the several forms. The inverted T shaped tooth upon the outer lip, formed by a lamella parallel to the lip-edge with a shorter one at its lower end, transverse to it, is characteristic of the group. P. Ponsonbyi n. sp. PI. II. figs. 1, 2, .3. Shell globose-depressed, with low conoid-convex spire, rounded periphery and convex base. Umbilicus one-sixth the diameter of shell, with flattened, nearly vertical w^alls, narrowing to a perfora- tion beyond the last whorl. Surface shilling, smooth except for extremely faint growth-wrinkles ; corneous-brown, with a chestnut- brown super-peripheral band on the body- whorl, appearing on the spire as a narrow sutural margiuation. AVhorls 5?, convex, slowly widening, the last decidedly wider, tumid on the latter half of the base, deeply and narrowdy constricted behind the outer and basal lips. Suture well and evenly impressed, abruptly and deeply deflexed in front. Aperture very oblique, rounded-oval, the lip forming three-fourths of the circumference. Outer lip broadly flaring, its inner edge bear- ing a short concave lamella, with a projecting compressed tooth at its lower end ; basal lip reflexed, with a similar compressed tooth. Parietal wall bearing a short, erect, straight lamina parallel with the basal lip, and having a very short V-branch at the outer end ; the inner termination not extending to the columella insertion. Alt. 5, greatest diam. 8*2, lesser 7*2 mm. Types from Mexico, exact locality not known, in the collections of John Ponsonby and the Academy of Natural Sciences of Philad. Like ventrosula and Richardsoni in the teeth of the lip, but more globose than either, parietal tooth with only a trace of the outer 18 PROCEEDINGS OF THE ACADEMY OF [1896. branch of the V, base more tumid, and umbilicus of last whorl more well-like. P. euglypta n. sp. PI. II, figs. 7, 8, 9. Shell obese, with low conic spire, rounded-angular periphery- near the top of last whorl, sloping outer wall and convex, tumid base. Umbilicated, a central perforation expanding at last whorl to form an umbilicus about one-sixth the diam. of shell, and with the wall rising almost vertically from its suture. Surface of outer 1^ whorls sculptured with sharp, strong and regular thread-like sig- moid riblets, subobsolete and more numerous by intercalation in the immediate vicinity of the umbilicus ; the inner whorls of spire smooth. Whorls 4^-41, the inner slowly increasing, last whorl much wider, very deeply constricted and excavated behind the outer and basal lips. Suture impressed, deeply descending in front. Aperture extremely oblique, transversely oval, the lip forming three-fourths of the circumference, upper and basal margins sub- parallel. Outer lip broadly flaring, with a short lamella on its inner edge, formed of a compressed, slightly entering portion joined T-like to a short lamella parallel to the inner lip-edge ; basal lip reflexed, bearing a compressed, entering tooth similar to the lower portion of the T on outer lip. Parietal tooth like a narrow, slanting V, the two branches united with the ends of the lip. Alt. 5*3. greater diam. 9"5, lesser 8'2 mill. Alt. 4"3, greater diam. 7"5, lesser 6'4 mill. Cinaloa (larger form) and Mazatlan (smaller form). A member of the P. ventrosula group, distinguished from veyitro- sula, Hindsi, Richardsoni and bicruris by the very strong, sharp rib- striation of the last IJ whorls. P. albicostulata n. sp. PI. II, figs. 4, 5, 6. Shell obese, with convex spire, periphery much above middle of body-whorl, and tumid base. Umbilicated, the umbilicus narrow and deep, with vertical walls, not much enlarging at last whorl, where it measures about one-ninth the diameter of the shell; within the umbilicus the last Avhorl has a deep spiral furrow, obliquely passing into the groove behind the basal lip. Surface shining, the latter two whorls sculptured with coarse whitish riblets with corneous brown spaces ; inner whorls nearly smooth, corneous brown. Whorls 54, weakly convex, the last very obtusely angular at its origin, becoming rounded and tumid on the latter half, deeply and narrowly 1896.] NATURAL SCIENCES OF PHILADELPHIA. 19 constricted behind the outer and basal lips. Suture slightly im- pressed, rather abruptly and deeply deflexed in front. Aperture oblique, oblong, the upper and basal margins subparal- lel ; outer lip reflexed, its inner edge bearing a concave lamina ending below in a denticle ; basal lip reflexed, impinging on the umbilicus, with a compressed tooth separated from the lamella on outer lip by a deep squarish sinus, a gentle swelling to the left of it. Parietal wall glazed with a translucent film, and bearing a long V- shaped tooth, the outer branch of which is short and not connected with the upper insertion of outer lip. Alt. 5*5, greatest diam. 85, lesser 7'5 mm. Type in collection of Mr. John Ponsonby of London. It is said to be from Mexico, and has the appearance of a northern Mexican shell. The strong, whitish rib-strise, narrow and nearly regular umbilicus with spiral groove within on the last whorl, and the aperture much as in euglypta, Riehardsoni and ventrosula, are a combination of characters amply sufficient to distinguish this species from other forms now known ; and while I am opposed on principle to the description of species without exact locality record, it seems best in some cases to depart from this salutary rule. I do not think any one will have difficulty in recognizing the species, as no other Polygyra having the apertural characters of this one, presents a similar um- bilicus or sculpture. EXPLANATION OF PLATES II and III. Polygyra Ponsonbyi n. sp., seen from below. Polygyra Ponsonbyi n. sp., anterior view. Polygyra Ponsonbyi u. sp., aperture, the plane of peri- stome at a right angle to line of vision, Polygyra albicostulata n. sp., from below. Polygyra albicostulata n. sp., anterior view. Polygyra albicostulata n. sp., aperture, the plane of peri- stome at a right angle to line of vision. Fig. 7. Polygyra euglypta n. sp., aperture, the plane of peristome at right angle to line of vision. Fig. 8. Polygyra euglypta n. sp., seen from below. Fig. 9. Polygyra euglypta n. sp., anterior view. Fig. 10. Polygyra matermontana n. sp., anterior view. Fig. 11. Polygyra matermontana n. sp., seen from above. Fig. 1. Fig. 2 Fig. 3, Fig. 4 Fig. 5, Fig. 6, 20 PROCEEDINGS OF THE ACADEMY OF [1896. Fig. 12. Polygyra materraontana n. sp., seen from below. • Fig. 13. Polygyra latispira n. sp., anterior view. Fig. 14. Polygyra latispira u. sp., seen from below. Fig. 15. Polygyra latispira n. sp., seen from above. Fig. 16. Polygyra latispira n. sp., aperture, the plane of peristome at a right angle to line of vision. 1896.] NATURAL SCIENCES OF PHILADELPHIA. 21 DESCRIPTIONS OF NEW SPECIES OF MOLLUSKS. BY HENRY A. PILSBRY. Marginella Veliei n. sp. Shell oblong, the body-whorl tapering (somewhat Conus-like) from the rounded shoulder to the base, spire conic. Surface brilliant, enamelled over the sutures and throughout, pale olivaceous-buff, slightly bluish around the middle of body-whorl, the outer lip white. Whorls about 5, nearly flat, the last convex above, rather flattened in the middle. Aperture about four-fifths the length of shell, its upper half narrow, lower half about twice as wide ; pale buff" inside ; outer lip slightly re- tracted at the two ends, smooth within, thickened by a moderate white callus outside, which is not pro- M. VelieiX^- ^uced upward to the preceding suture. Columella bearing four plaits, the lower three subequal, upper one slightly smaller and more deeply inserted. Alt, 15, diam. 7*1 ; alt. of aperture 12 mm. Alt. 14'(3, diam. 7'5 ; alt. of aperture 11*8 mm. Boca Ciega Bay, Florida (Dr. J. W. Velie!). This species resembles M. Hindsi Petit in outline, Imt the callous rib of the outer lip is not continued upward as in that species. It is notable for the rather slender and tapering form of the body- whorl and slight inward bend of the outer lip. It is somewhat re- markable that so large a Marginella as this has until now escaped notice on our Florida coast. Siphonalia semiplicata n. sp. Shell fusiform, tapering about an equal distance above and below, solid and strong, gray with some indistinct brownish patches. Whorls about 8, nucleus smooth (partly lacking by erosion) ; 5* later whorls sculptured with cord-like spirals about equal to their inter- vals in width, about 11 in number on penultimate and three preced- ing whorls; last Ih whorls having short, sometimes indistinct, sub- vertical waves at the shoulder, the preceding whorls merely convex, with no vertical folds. Last whorl contracted and produced at base 22 PROCEEDINGS OF THE ACADEMY OF [1896. as usual, the siphon nearly straight, a little recurved. Aperture livid brown within, contained 1"8 times in length of shell ; outer lip regularly arched, multilirate within, the lirse extending to within about I2 mm. of lip-edge; columella concave above, straight, verti- cal and more heavily calloused in the middle, slanting to the left below. Alt. 47, diam. 24 mm. Yokohama, Japan. Allied to S. ficsoides, fiiscolineata, etc., but in this species the ver- tical waves of the shoulder are entirely absent on the spii e ; the canal is nearly straight. In this connection it may be well to call attention to the fact, kindly communicated to me by Mr. J. Cosmo Melvill, that Siphon- alia Stearnsii Pilsbry is identical with S. psexidohuccinum Melv. and S. hyperodon Pils. is the same as IS. Mikado Melv. Mr. Melvill's names were proposed in the Journal of Conchology (Leeds), V, p. 348, Ischnochiton aspidaulax n. sp. Shell oblong, slightly narrower in front, moderately elevated, carinated, the side slopes nearly straight. Surface somewhat shin- ing, and (a) dark olive at the sides, a light olive band dappled with darker spots along the ridge, or (6) light dull bluish dappled with brown, and with some snow-white patches on valves ii, iii, v and vi ; yellowish at the apices of valves. Median valves not beaked, the sutures concave. Lateral areas well defined, but only a trifle raised, sculptured with numerous dis- tinct, unequal radial grooves, not extending to the apex, and parted by unequal spaces, densely sculptured with oblique or Y-shaped scale- like granules, the apices of the V's directed toward the beaks. Central areas very densely and minutely sculptured with longitudinal irreg- ular wrinkles, somewhat converging, becoming finer toward the ridge, coarser in front of the diagonal line. Posterior valve with the mucro slightly projecting, somewhat in front of the middle, pos- terior slope somewhat concave. Interior bluish, with olive stains behind the valve-callus. Sinus rather i\arrow, straight and smooth, angular at the sides. Valve i with 10, valves ii to vii with 1-1, valve viii with 10 slits. Teeth rather long, sharp and smooth. Eaves narrow, deeply grooved above the teeth. Girdle covered with compactly, irregularly imbricated glossy scales, very weakly striated, and measuring "8 to '25 mm. in width ; each scale olive-blackish with a broad outer border of white. In a 1896.] .NATURAL SCIENCES OF PHILADELPHIA. 23 general view, the girdle appears light olive with an ill-defined dusky bar opposite each valve. Length 18, breadth 9 mm. (exclusive of girdle). Angle of di- vergence 119°. Panamic region, exact locality not known. Specimens of this elaborately sculptured Ischnochiton were re- ceived from Mr. W. J. Raymond some years ago. Mr. E. R. Sykes, of London, has kindly compared it with the type of/, dispar Sowb., and informs me that it is quite distinct, confirming the opinion I had already formed from a study of the description and figures of that species. From other West American species it is readily dis- tinguished by the peculiar sculpture, dorsal keel and the coloration of the girdle scales. Sagda (?) Gabbi n. sp. Shell depressed, with low, conoid-convex spire, round periphery and somewhat flattened, convex base, rather deeply indented around the minute umbilical perforation ; solid though rather thin ; whitish corneous or faintly buflf; the surface rather dull though shining, smooth except for irregular, very faint growth-marks. Whorls about 5i, convex, slowly widening, the last decidedly wider, not descending in front. Suture impressed and narrowly translucent- margined below. Aperture subvertical, a little oblique, lunate ; peristome evenly curved, sharp-edged, the columellar margin lined with white callus inside, and reflexed in the vicinity of the umbilical perforation, nearly concealing it. Alt. 7, greater diam. 11, lesser diam. 10 mm. (Type). Alt. 8, greater diam. 12, lesser diam. 10'8 mm. (specimen in Pon- souby Coll.). San Domingo (W. M. Gabb !). Compared with Helix effusa Pfr. (Monographia, V, p. 105, Tryon, Manual II, p. 163), of which part of the original lot collected by Smith are before me, this species is more solid, with smaller perfor- ation, smoother surface and fewer, more rapidly widening whorls ; but it is especially distinguished by the different form of the peris- tome. In effusa the basal lip (in a ventral view of the shell) is seen to bend forward in a broad convex lobe, the outer point of the curve extending as far forward as the insertion of the outer lip ; and upon^ the base the usual direction of the arcuate growth-lines is reversed. In the new species, while there is a slight bend, no such effuse con- dition of the basal lip is developed. 24 PROCEEDINGS OF THE ACADEMY OF [1896. This species is described from four specimens collected by Gabb (the types), and one in the collection of Mr. John Ponsonby, of London. The latter is slightly larger, and, at first glance, seems to have the aperture more vertical, but this is caused by the breaking away of the upper portion of the lip-edge. The columellar callus becomes a little heavier, slightly convex, toward the lower end of columella. Upon breaking a specimen a minute embryonic shell was found. The species is therefore prob- ably viviparous, as I have shown some other species of Thysanophora and Sagda to be. The callous lining of the interior in the columellar region is conspicuous in this species but absent in H. effusa Pfr. Both species seem to me referable to Sagda rather than to Thysano- phora; but the two genera are intimately allied. 1896.] NATURAL SCIENCES OF PHILADELPHIA. 25 THE BEES OF THE GENUS PEKDITA F. Smith. BY T. D, A. COCKERELL. Ill attempting to teach entomology to the students of the New Mexico Agricultural College, the difficulty was early felt, that there existed no work treating in an adequate manner of any group of insects obtainable in the vicinity. While it was possible to indicate the outlines of the subject without any very profound knowledge of the insects which were collected and studied, it appeared to the writer that this superficial method of work could not lead to the best results. It is quite true that an ordinary student has not time to master even the families of insects ; but the writer has long felt persuaded that the plan of teaching the elements without entering into detail is essentially a vicious one, calculated in extreme cases, even to convey a totally false impression of the true lessons of biology. In the first place, the main purpose of biological study in educa- tion is not so much to load the mind with information, as to prompt a habit of observation and deduction. Owing to the unfortunate trend of the present educational system, the students almost inva- riably come to the entomology class prepared to learn by heart any lessons that may be assigned to them, but very ill-prepared to notice what has not been actually pointed out. It is, perhaps, not an exaggeration to say that the average junior or senior student in a college possesses less inclination and ability to notice and compare than a child of from five to ten years of age. The entomological studies, if successful, should tend to break down this acquired mental habit, and restore in some measure the inquisitiveness of childhood. Therefore, nothing can be worse than limiting the student's knowledge by what may be written in a text- book, and checking his budding interest in every direction by " I don't know," with the implication that it is no use trying to find out. The idea that some facts are to be regarded by the student, and all others ignored, is an entire perversion of the proper spirit of biological inquiry. 26 PROCEEDINGS OF THE ACADEMY OF [1896. Another consideration is, that after all the cell, the individual and the species are the three natural units in biology, without a just conception of which, all reasoning must be futile. The orders, fami- lies, genera and other higher groups do not stand at all on the same plane, being essentially artificial arrangements for convenience in classification. Consequently a student who might be thoroughly acquainted with the higher groups and ignorant of species, would be very little prepared to form just conceptions of the phenomena of life. When these ideas dawned upon the writer, he was somewhat dis- concerted to reflect that in the whole range of zoology he possessed an intimate acquaintance with only two series, the slugs in Mollusca and the Coccidse in Insecta. Of the former, which might have been used in zoological studies, there is but one species in New Mexico, and that not found in the neighborhood of the college ; of the lat- ter, the species are more numerous, but very unsuited for the pur- pose required, since they are exceptions to almost every ordinary entomological rule. It is perfectly true, that there already exist many very admirable monographs of North American insects of diflfereut groups ; but there are two reasons why even the best of these do not entirely serve our purpose. The first is, that comparatively little collecting has been done in southern New Mexico, so that many of our very common species are even unknown to science, and, therefore, not to be found in the monographs ; the second, that very few of the pub- lished writings contain anything like a careful account of the habits of the species. One of the very first lessons that the student has to learn is that structure is as intimately related to environment, as lock to key, and a work which practically ignores one side of this question cannot be entirely satisfactory. The nearest approximation to what is wanted is found among the higher lepidoptera, which are illustrated by such admirable works as those of Scudder and AV. H. Edwards. Yet these insects are not very easily studied by a beginner, except in a superficial way, nor is their classification yet upon a perfectly sound basis. So finally, it was concluded to take up the bees and endeavor to work them up in such a manner that they might be used as desired. They are good typical insects, their principal structural characters are easily observed, their habits are most interesting, and they abound in New Mexico. Moreover, the bee-studies go very nicely hand-in-hand 1896.] NATURAL SCIENCES OF PHILADELPHIA. 27 with flower-studies undertaken in botany, the relations between bees and flowers being among the most fascinating phenomena in natural history. The present essay on Perdita is the first step toward the realiza- tion of the above mentioned ideal. Imperfect as it undoubtedly is, it has grown like a mushroom under the hands of the writer ; so that the probability of finishing the whole series of bee-genera seems remote indeed, if each is to increase in a similar fiish ion. Seventeen North American species of Perdita were known before the writer began to study them ; of these, two are not considered valid, but 55 have been added, bringing the list up to seventy ! Thus, in number of species described, Perdita becomes at a bound the largest of North American bee genera. MATERIAL EXAMINED. By far the greater part of the material studied has been collected by the writer in New Mexico. With great kindness, Mr. AY. J. Fox loaned a series of specimens containing his Lower Californian types, and all the species of Cresson except cephalotes, as well as several herein described as new. In various other ways, such as comparing types, Mr. Fox has throughout the whole investigation given invaluable assistance. Mr. C. F. Baker was so good as to send me the specimens he and his wife had collected in Colorado, which included some new forms. Mr. C. Robertson has given some very valuable information regarding the habits of the two eastern species. Some interesting species have been found by students of the college. Miss Mae Gilmore, Miss J. E. Casad, Mr. Alfred Holt and Mr. C. Rhodes, as duly indicated below. My botanical col- league, Professor Wooton, found one new species. The writer has seen all the species treated of, except cephalotes, halictulus and bicolor. Of the 70 species, 26 are known in both sexes, 26 only in the ^ , 18 only iu the 9 . 23 are at present only known from uniques. The flower-visiting habits of 50 species are known. The nesting habits are as yet unknown. CHARACTERS USED. It is hoped that those who may have occasion hereafter to describe species of Perdita will read this section, as a study of the published descriptions shows that some important characters are almost always omitted. 28 PROCEEDINGS OF THE ACADEMY OF [1896. The coloration of the head and thorax is black, green or blue ; frequently the parts are not colored alike, the metathorax especially- being usually bluer than the mesothorax and scutellum. The metallic color does not extend on to the abdomen, except to a slight extent in intermpta. The sculpture of the metallic portions differs, and a good character is found in the smoothness or otherwise of the mesothorax ; in some it is very smooth and shining, in others gran- ular or striatulate and comparatively dull. The dulness or other- wise of the front, and the puuctation of the area close to the ocelli^ may also be used. The pale markings may be absent ; when developed they are from pure white to deep yellow, never red, though the yellow of many males may be reddened by cyanide. The reddest color ob- served is in the bright orange-rufous of the latter end of the abdomen in crotonis, and the orange-rufous legs of foxi. The abdomen, as in latior, may be bright ferruginous. These colors are entirely differ- ent from the scarlet induced by cyanide. In some species which live on yellow flowers {hdeola, heata, larrece) the whole body -color is deep yellow, the dark markings being reduced to a mininmm. No species is known similarly white, nor is any species all rufous like some forms of Noinada. The head may be comparatively small, round, or broader than long or longer than broad ; in some species it is very large and sub- quadrate. The males may or may not have a conspicuous tooth or spire on the cheeks beneath ; this character appears to be a valid specific one, but appears in species which are not closely allied, (e. g., larrece and pulchrioj-'), while it distinguishes certain forms from their closest allies, as pulchrior from pallidior, the latter having un- armed cheeks. It is to be observed that in the Mutillid genua Sphcerophthahna a similar state of affairs occurs, only it is the females that possess the armed cheeks. Thus *S. montivaga is ex- tremely like S. megaeantha, but lacks the spine on the cheeks. S^- towneyi also differs from its allies by its spinose head. The charac- ter is, therefore, one of those which has been termed " kaleido- scopic." The mandibles may be bifid at the tip (latior, texana), or may be notched within (sphceralcece 9 ) or even present a distinct tooth on the inner side (oRneifrons). They are, however, usually simple, and more slender in the males. In the females of the albipennis group they are very stout and strongly elbowed, quite different from the 1896.] NATURAL SCIENCES OF PHILADELPHIA. 29 males. There is also a marked sexual difference in the mandibles of venfralis. The tongue differs in length and in the degree of development of the hairs. As will be seen below, the tongue has on two or three occasions proved useful in distinguishing allied forms (as affinis and senecionis), but it has not been studied throughout the series. In one instance, a useful distinction was found in the relative lengths of the joints of the maxillary palpi. The form of the clypeus differs very much both between the spe- cies and the sexes of the same species (e. g., ventralis). For conven- ience I have compared the shapes noted to the outlines of different kinds of hats. The degrees of hairiness of the face and cheeks, as also of the thorax (especially of the mesothorax) offer useful characters. The hairs are usually white, but may in part be grayish or brownish, or even, in a yellow species (beata), yellow. They are very rarely (cdbovittata) dense enough on the face to obscure the markings. The antennae present different grades of color (usually paler be- neath) from yellow and orange to black. In the albipennis group the color of the flagellum has served to distinguish the males of allied forms. The face markings at first seem complicated and hard to describe, but are easily reduced to a simple system. The face may be wholly dark, but if the pale marks are much reduced they are generally seen to linger last upon the clypeus. An exception to this is found however in semiccerulea, with its shining yellow mark on each side of a perfectly dark clypeus. The clypeus may be wholly light, usually retaining a black dot on each side near the margin. The clypeal dark markings appear frequently in the form of two longi- tudinal black bars, as in numerata. The lateral light markings of the face are commonly triangular, the inner angle being about opposite the dot on the clypeus, and the upper angle usually on a level with the antennal socket on the orbital margin. Soaietimes the lateral mark extends up along the margin of the orbit much further ; and it may terminate variously, being either pointed or truncate. The shapes of the lateral face marks afford excellent specific characters. Above the clypeus, between its upper border and the level of the anteunse, is the siipradypeal mark, which differs very much in its degree of development, and even in its shape in some allied species. It may be produced upward in the median line to an enlarged yel- 30 PROCEEDINGS OF THE ACADEMY OF [1896. low mark ou the front, the frontal mark, but this is not very com- mon. Finally, just below each antenna may be a small subtriangular mark, which I have called the dog-ear mark, because of its resem- blance to the ear of a hound, first observed In the $ form described as canina. In the males the face is frequently all yellow or white up to the level of the antennce; and then good characters are found in the degree of its further upward extension, and in the form of its upper limit. The face markings are nearly always conspicuously different in the sexes, but not so in alhovittata and the albipermis group, nor in luteola, nor the texana group. The pale markings of the thorax are confined to different degrees of yellow on the prothorax, often affording good characters, and occasional very characteristic yellow patches on the pleura, except in mexicanorum, which has a yellow postscutellum, and luteiceps, which has a little yellow on mesothorax and scutellum. Two spe- cies, punctoslgnata and cephalotes, have the thorax yellow with black markings ; marcialis has it yellow with green markings, the meso- thorax being green with yellow lateral margins. The wings may be simply hyaline or milky-hyaline, or slightly smoky; never really dark and never spotted or banded. The nervures and stigma may be dark brown, light brown, yellowish or colorless ; the stigma is usually hyaline centrally. In the texana group the stigma is hardly developed. Very good characters are 'found in the venation. The marginal cell differs greatly in size and length, but I never saw one so long as to suggest the condition of Calliopsis. It may be obliquely or squarely truncate. It may have the portion below the stigma (substigmatal) longer than that beyond ( poststigmataV), but usually they are about equal or the latter is longer. There are but two sub- marginal cells ; and the shape of the second, whether triangular or how much narrowed to the marginal, should in each case be noted. The so-called second submarginal is morphologically the third, the true second of genera with three submarginals being absent. On one side of the type 9 of obscui-ata, the true second submarginal actually appears, small, triangular and petiolate, much as in the Larrid genus Plenoculus. The third discoidal cell may be very weak or even entirely want- ing, according to the development of the second recurrent nervure. 1896.] NATURAL SCIENCES OF PHILADELPHIA. 31 The legs may be dark or yellow, or variously marked with these colors, and the proportions of dark and light, though variable, afford good characters within reasonable limits. The anterior tibise are usually yellow in front at least. The abdomen differs somewhat in shape, and may be either wholly dark or variously banded or spotted. In every case it should be carefully described, and the color of the ventral surface should also be mentioned. The $ genitalia differ in one or two species I have examined, but I have not studied them sufficiently to be able to introduce them into the classification. In addition to the above structural and colorational characters, too much stress cannot be laid on the importance of noting the exact localities and the flowers visited. Without the assistance derived from such information, it would have been impossible to unravel the mentzelke series, or satisfactorily arrange the forms allied to affirds. Further, facts of this kind are invaluable in the difficult task of correctly associating the sexes. The time of flight should also be carefully noted. Some species are vernal, others (the great majority) fly in late summer and autumn. GEOGRAPHICAL AND VERTICAL DISTRIBUTION. The species of Perdita are characteristic of the arid region of North America. Of the 70 species, 49 are found in New Mexico, and of these, no less than 34 are in the Mesilla Valley, in the Middle Sonoran (= lower part of Upper Sonoran) zone, at 3,800 feet. Ascending the Valley of the Rio Grande, four species were taken at San Marcial, one at Socorro and nine at Albuquerque, but at none of these places was more than a few day's collecting done. One species was found at San Augustine, on the east side of the Organ Mountains, but has since been observed in the Mesilla Valley. There can be no doubt that Perdita abounds throughout the Upper Sonoran zone in New Mexico. At Santa Fe, 7,000 feet, in the transition zone of New Mexico, a good deal of collecting was done in two seasons, but the species of Perdita do not appear to be so numerous as in the Upper Sonoran. Only seven species were taken, although one or two were very numerous in individuals. In the mid-alpine zone no species were seen, either in New Mexico or in the three years residence in Colo- rado. 82 PROCEEDINGS OF THE ACADEMY OF [1896. In Colorado, species of Perdita have been found at La Junta, Fort Collins, Estes Park and Glenwood Springs. On August 12, 1887, I found a species at Cottonwood Creek, Pleasant Valley, Fre- mont County, Colorado ; it was sent to Mr. Ashmead, but the species WAS not determined. In my note-book I recorded that it was 3^ mm. long, head black, thorax gray, abdomen red-brown; surely it was a new species, different from any herein described. A few species of Perdita have been found in other parts of the west — three in Lower California, three in California, three in Nevada. Two are known from Texas, one from the State of Chihuahua, Mexico. Two vaguely from Mexico. In the Eastern States, Perdita is represented by only two species, odomaculata of the northern region, from Illinois to New Hamp- shire ; and obseurata in the south, Georgia and Florida. One of the Rocky Mountain species, alhipennis, extends northeastward to South Dakota. As regards vertical distribution, one species, spJueralcece, extends from the Mesilla Valley to Santa Fe, but the Santa Fe form is an easily distinguishable race. P. lepachidis extends unaltered from Socorro to Santa Fe ; and zebrata and chamcesarachcB extend from Albuquerque to Santa Fe. P. austini and bigelovice extend from the Mesilla Valley to Albuquerque. THE FLOWERS VISITED. It may be laid down as a general rule that each species of Perdita visits normally but one species of flower, but occasional speci- mens may be found on flowers to which they do not normally belong. The exceptions to this rule are found in P. odomaculata visiting Solidago, Coreoj^sis and Aster ; P. cladothricis visiting various Compositee as well as Cladothrix ; P. pedidis visiting Pedis, Tribulus and Wedelia; P. fallax visiting Bigelovia, Verbesina and Pedis; P. phyiiiatce visiting Bigelovia and Gutierrezia ; and P. seviicrocea visiting Solidago, Bigelovia and Gutierrezia. In the case of several uniques, it is not certain that they normally belong to the flowers on which they were found. Thus a single P. pnlchrior was found on Bigelovia at Las Cruces, and it would have gone in as a Bigelovia species but for its previous discovery on 3feiitzelia at Albuquerque. In the Mesilla Valley, toward and at the base of the Organ Mountains, are many species of flowers which should by all analogy have their species of Perdita. But theoppor- 1896.] NATURAL SCIENCES OF PHILADELPHIA. 33 tuiiity has not offered to make excursions to determine this at the right season, and we can only surmise that some of the uniques taken on Verbesina, Bigelovia, etc., will be hereafter found abun- dantly attached to some other plant in the neighborhood. The flowers visited are cited in their systematic order, following the arrangement of Eugler and Prantl, as recently adopted in the A. A. A. S. list. The number of known Perdita flowers is 25, of which 13, more than half, are Compositie. Twelve species of flow- ers have furnished more than one Perdita species, the greatest num- ber (12) being from Bigelovia ivrightii. It is to be explained in reference to the names used for the flow- ers, that the writer is in favor of using the earliest generic name in every case, when not jireoccupied by a valid homonym ; and also the earliest specific name when not preoccupied by a valid homonym in the same genus. But he is entirely opposed to the practice of ■displacing names because antedated by synonyms, which are not and never were deserving of recognition ; and he does not consider a varietal name invalid because previously used for a different spe- cies, or a variety of a different species, in the same genus. He thus objects to the substitution of Chondrophora for Bigelovia (or Bige- lowia), or of Covillea for Larrea. Likewise of ya.r. jnlosus for var. villosus of Aster ericoides* SALICACE^. (1). Salix. The willow-frequenting bees at Las Cruces in May are Perdita salicis, P. nnmerata, Andrena salicinella Ckll., Andrena n. sp., Halictus sp., and Prosopis sp. P. salicis abounds, but of numerata only one was taken. AMARANTHACEJE. (2). Cladothrix cryptantha S.Watson. P. cladothricis abounds on this ; it was rather surprising to find so simple a flower so abundantly visited by a particular species of bee. The genus Cladothrix has cited in the Index Kewensis only two species, both from Western North America. NYCTAGINAOE^. (3). Wedelia iNCARNATA (L.) Kuntze. Visited by P. pectidis. The Boerhaavia, common at Las Cruces, is not visited by Per- dita; while the large purple mirabilis is, of course, a moth flower, and is visited by Deilephila lineata. 34 PROCEEDINGS OF THE ACADEMY OF [1896, CAPPARIDACEiE. (4). Cleome serrulata Piirsh, This is not found growing wild at Las Cruces, but it abounds from Albuquerque to Santa Fe and northward into Colorado, being visited in great numbers by Perdita zebrata. There is a not uncommon white-flowered form ( C. albiflora) which I observed at WatrouB, N. M., and other places. While P. zebrata is the only Perdita of the Cleome, it has to compete with numerous bees of other genera. At Santa Fe, on August 2d, I noted that Nomia punctata was in full force on ihe^Cleome, its hind legs loaded with the green pollen. Other Cleome bees at Santa Fe are Melecta miranda, Anthophora, Megachile, Melissodes and Bombus. At Albuquerque a Cal- liopsis is common on the Cleome ; and I saw at this locality on August 16th, a humming-bird visiting it. LEGUMINOSJE. (5). Prosopis juliflora var. glandulosa (Torrey). The mes- quite furnishes Perdita exclamans and P. punctosignata. Mr. Alfred Holt has also taken an Anthidium on mesquite at Las Cruces, It will be noted that the generic name of this plant is the same as that of a genus of bees. This inconvenience might be avoided by spelling the bee-genus Pi'osapis, as has already been done by Mr. Ashmead (Hym. Colo., p. 31). The botan- ical genus has priority. The mesquite extends in modified form to sea-level in the neotropical region ; it is, in fact, essen- tially a neotropical type. ZYGOPHYLLACEJE. (6). Tribulus maximus L. Visited by P. pectidis. The plant cannot be other than maximus, but it does not agree in detail with published descriptions. I have found the plant (though not the bee) as far north as La Junta, Colorado. (7). Larrea DivARiCATA var. TRiDENTATA (DC). At San Mar- cial were found on this P. marcialis, P. larrece, P. larrearum and P. semicmndea. The P. larrece is colored yellow like the flowers of the plant. The genus Larrea consists of four or five species, confined to the Mexican region and the Argen- tine Republic. Our species is a variety of one of the Argen- tine ones. EUPHORBIACE^. (8). Croton texensis (Klotzch) Muell. Arg. At Albuquerque I found numbers of P. crotonis on this. The same plant is 1896.] NATURAL SCIENCES OF PHILADELPHIA. 35 common at Saata Fe, but yields no Perdita. The constancy of Perdita spp. to their proper flowers was well illustrated at Albuquerque, where on the Cruton was only P.crotonis, while on the Cleome only 8 paces distant was only P. zebrata. At Las Cruces, Croton neomexicanus is common, but I found on it no Perdita, or even bees, only Larridse and especially Phil- anthidce, including Aphilanthops taurulus. This was on Sep- tember 25th, and only staminate flowers were to be found. Croton is a very large genus, with many neotropical species, but also found in the tropics of the Old World. MALVACEiE. (9). Sph^ralcea angustifolia Spach. Abundant and variable from Las Cruces to Santa Fe, in the former locality furnish- ing P. latior and P. sphceraleece ; in the latter a distinct race of sphceralcecB. At Santa Fe the Sphceralcea is visited also by Epeohis, Bombxis, Colletes, Melissodes, etc. At Las Cruces it is principally visited by Dladasia. LOASACE^. (10). Mentzelia nuda (Pursh) Torr. and Gray. Visited at Santa Yi by P. mentzelke, and at Albuquerque by P. paUidior and pulchrior. It is a favorite i?ow6its flower. The genus goes south to Chili. UMBELLIPERiE. (11). Hydrocotyle umbellata L. Mr. Robertson reports P. obscuraiaiYom this. I have never myself found any Perdita on an Umbellifer. SOLANACE^. (12). Cham^saracha coronopus (Dunal) A. Gray. P. cIuwkb- sarachce abounds on this at Albuquerque, and was also taken on it at Santa Fe. The genus is a small one, the Index Kewensis cites 1 Texas, Mexico, 2 California (here includiug our coronopus), 1 Mexico, and 1 Japan. Thus it is not ap- parently of neotropical origin. COMPOSITE. (13). GuTiERREZiA SAROTHK.E (Pursh) Britt. and Rusby. At Albuquerque were found on this, one each of P. austini, gutierrezice and pallidior — the last doubtless accidental. (14). GuTiERREZiA SAROTHR.E var. MiCROCEPHALA (Gray) Coul- ter. This is common at Las Cruces, and has furnished P. austini, semicrocea, luteola, phymatce, tarda and cladothrieis. On September 25th, a single 9 verbesince was also taken on 36 PROCEEDINGS OF THE ACADEMY OF [1896 it, but this was undoubtedly accidental, as verbesinoe was extremely numerous on Verbesina close by, and if it had anything to gain by visiting Gutierrezia, it would be seen there more than once. The genus Gutierrezia goes south to the Magellan Strait region. It is moderately numerous in species in the Mexican (Sonoran) region and arid region of the U. S., and again in in the southern part of the neotropical region, as far north as Chili. (15). SoLiDAGO CANADENSIS L. Fig 1. This common Goldcn-rod has a wide range over the continent, and extends from Las Cruces to Santa Fe, being usually seen on or about the ace- quia banks. Mr. Robertson records it as one of the plants visited by P. octomacu- lata in Illinois ; in Colorado Mr. Baker has taken from it bakerce, affinis, sexmac- ulata var. and rectangulata. At Las Cruces it furnished fair numbers of semi- erocea, and a single grandiceps. It is worthy of note that it is not at all visited by luteola, or indeed any of the Bigelovia species except semicrocea. (16). Bigelovia WRiGHTii Gray. Fig. 2. This is the very abund- ant Bigelovia of comparatively dry sandy ground between the river bottoms and the benches at Las Cruces and Albuquer- que, N. M. Hitherto it had been confounded by us with B. rusbyi, owing to a specimen, apparently quite identical with our plant, having been so named at the California Academy of Sciences. As I was somewhat uneasy about this determination, Professor Wooton at my request sent a specimen to Columbia Col- lege, and word comes back that it is assuredly ivrighiii and not rusbyi. This explanation is need- ed, because I have sent out various insects labelled as from B. rusbyi. Besides being most prolific in Perdiia species, this plant is won- derfully attractive to many kinds of insects. At Albuquerque I got from it P. bigelovice, and among other things the ant, Tap- inoma anale Andre, and quanti- FiG. 2. 1896.] NATURAL SCIENCES OF PHILADELPHIA. 37 ties of a pretty Chalcidid, Orasema viridis Ashraead (Det. Dep. Agric). The latter is new to the U. S. Fauna, having been only lately described from a specimen found at Tepic, Mexico (Proc. Cal. Ac. Sci., 1895, p. 553). At Las Cruces I found on B. lorightii plenty of P. luteola especially, accompanied by semicrocea, oeneijrons, phymatce, fallax, higelovi(je, nilidella, austini, while cladothrieis, pulch- rior, macidipes and pellucida were occasional. Here the flowers are peopled by the same species of ant, Tapinovia anale Andre (det. Ernest Andre) as was found on them at Albuquerque ; its color is such as to render it inconspicuous. Three species of beetles are particularly noticed on the flow- ers, Chauliognathus Scutellaria Lee, Crossidius pulchelhis Lee, and Clems abruptus Lee. (det. Wickham), of which the first two are yellow like the flowers, with some black ; and the last (appearing in October) is beautifully marked with red, resembling at a glance Sphcerophthalma heterochroa, which is found in the same vicinity, though never on flow- ers. Sundry Coccinellidje, Chrysomelidse and Bruchidre also frequent the flowers. Some Heteropterous insects found on the flowers are colored yellow to escape observation ; one of these, Phymata fasciata, is predaceous, and a serious enemy of the bees. So there are also yellow or yellowish Thoniisidse, and certain Bombyliidie and Trypetidse among the Diptera which visit the Bigelovia flowers are more or less strongly yellow — more especially the beautiful little Phthiria sulphu- rea Loew (see Psyche, January, 1895, p, 188). Among Hymenoptera, besides various bees, are found several Phil- anthidpe, Scoliidse, Eumenidpe, Chalcididse, Chrysidida^, etc., some of the species being new or rare in collections, for ex- ample, Aphilanthops taurulus Ckll., A. quadrinotahis Ashm. (heretofore only known from a specimen found at Denver, Colo.), Acanthochalcis nigricans Cam., and Chrysis mesillce Ckll. The genus Bigelovia belongs especially to the arid region, but there are two species in Ecuador. (17). Chrysopsis villosa (Pursh) Nutt. This is properly a mountain plant (abundant, for example, in the mid-alpine of Colorado), but several vigorous plants are growing in a dry watercourse near the N. M. Agricultural College, the seeds having doubtless been washed from the Organ Mount- ains. On one of these I caught the unique of P. vespertilio. At Santa Fe I watched some Chrysopsis villosa, but only got one specimen of an Antlwphora. (18). Aster ericoides var. villosus (Michx.) Torn and Gray. Mr. Robertson reports this as visited by P. octomaculata. 38 PROCEEDINGS OF THE ACADEMY OF [1896. (19). Aster CANEscENs var. viscosus (Nutt.) Gray. Fig. 3. At Las Cruces this is freely visited by P. asteris. Two species of Aster which are common at Las Cruces, A. spinosus and A. hesperkis, have produced no Perdita. The former is a weed of waste grounds, the latter occurs on the acequia banks, so they may not be natives of the immediate region. It has occurred to me that by watching the bees on a flower, some evi- dence might be obtained as to the length of time the flower has grown in the local- ity. Thus, to take an extreme class of cases, garden exotics are visited by com- paratively few bees, and of course have none peculiar to them, as P. asteris to Asler caneseens var. (21). (22). (20). Lepachys tagetes ( James)Gray. Visited by P. lepachidis ; also, at Santa Fe, by Melissodes, Agaj)oste- mo7i, Halictus and Bemhex. -/ffScfe Helianthus annuus L. Fig. 4. The sunflower is the flower of P. albipennis ; very rarely a verbesince may also be found upon it. Other sunflower bees ixrePanurgiis,3Ielis- sodes and Andrena, all at Las Cruces. Phymata fasciata also occurs on the sunflower heads. It is to be noted that the Andrena found on sunflowers at Las Cruces is not the same as Mr. Robertson's Illinois A. heliantld. Verbesina encelioides (Cav.) Gray. Fig. 5. At Las Cruces this produces commonly P. ver- besinoi, rarely beata, perpulchra Fig. 4. and albovittata, and occasionally or accidentally albipennis, var. vagans, latieeps and fallax. In October I noticed Apis mellifica visiting the flowers in numbers ; the honey-bee flies longer and visits more species of flowers than any wild bee I know, and m^ust surely prove rather a serious competitor of the wild species. The competition would be most severely felt, of course, in those years when, owing to unfavor- able weather, the flowers were less numerous than ordinary. 1896.] NATURAL SCIENCES OF PHILADELPHIA. The yellow bug Phymata fasciata Gray, abounds on the Verbesina ; on September 28th, I found one which had caught a P. verbesince. This Phymata not only preys on bees, but the butterfly, Lycama exilis, the house fly, Musca domestica, and doubtless many other insects. Another enemy of bees which is found on Ver- besina is a Thomisid spider ; on September 22d, I found one of these had caught a P. verbesinw. There are various other Verbesma bees, in- cluding the pretty Agapostemon melliventris, which also appears in the spring, then visiting Sisymbrium and Streptanthus. (23). BiDENs ARisTOSA (Michx) Britt., (= Core- opsis ARiSTOSA Michx). Mr. Robertson cites this as visited by P. octomaculata. 39 tlG. 5. (24). Senecio douglasii DC. On this Professor Wooton found P. senecionis, as also an Anclrena and other bees. (25). Pectis papposa Gray. This is visited by P. pedidis, but cladothricis, fallax and biparticepshave also been taken on it, while once only a luteola was seen in the net after sweeping Pectis. The flowers are frequented by an ant, Dorymyrmex pyramicus Rog. (det. Andre). One also finds upon them Panurgus (commonly) and Epeolus (rarely), as well as sun- dry Philanthidpe and Bombyliidae, etc. The genus Pectis has many neotropical species, extending even south to the Argentine Republic. It has also AVest Indian representatives in Cuba, San Domingo and Cura9oa. In reviewing the above list of plants, it will be readily seen that Perdita does not usually frequent the boreal types of flowers, but rather those which extend northward from the neotropical region. This, taken with the known distribution of the genus, strongly sug- gests that in the main we have to do with an austral series of types, which have spread northward and become largely differentiated into species since the glacial epoch. P. octomaculata, however, must be looked upon as a survival from preglacial times ; and here it is especially significant that affinis and senecionis, which more especially represent octomaculata in the west, are the very ones which visit boreal flowers, Solidago and Seneeio to wit. Further, bakerm which does indeed visit Solidago also, shows every indication of being a recent derivative from the Cleome type zebrata ; an in- 40 PROCEEDINGS OF THE ACADEMY OF [1896. stance, in fact, of the neotropical immigrants adapting themselves through modification to subboreal conditions. Another thing that deserves notice is the relationship between the size of the bees, the length of their tongues, and the kinds of flowers. It would appear that a longer tongue is not always developed inde- pendently to meet requirements, but that the total size of the bee may be increased, and with it the tongue. Or conversely, the size of the bee may be reduced. Speculations of this kind are, perhaps, not very profitable, but it will be advantageous to give the facts which suggest them. Close to the N. M. Agricultural College Verhesina encelioides und Bigelovia ivrigJitii grow in the utmost profusion. In September col- lections were made off both, the plants being but a few yards from one another, with the following results: — Verbesina : — Perdita, Calliopsis, Pamir'gus, Melissodes, CcelioxySy Andrena, Epeolus ; but on October 5th when the Bigelovia was getting over, Halidus ligatus, H. pedoraloides and Agapostemon inelliven- tris. Bigelovia: — Perdita, Agapostemon, Anthophora (small species), Megachile (one), Colletes, Halidus $ , Halictus stultus 9 , Prosopis^ Nomia nevadensis. Thus it will be seen that the bees of these two plants were almost entirely of different genera in September, those on the Verbesina being Apidte with few exceptions, those on the Bigelovia largely AndrenidjB. But as the Bigelovia began to be over, the large Andrenidre visited the Verbesina, which had given a second crop of flowers. Now although Perdita appears equally in both lists, the species are different, and if we except unique specimens, as we justly may, those on the Verbesina are of larger size, those on the Bigelo- via comparatively small. The abundant larger verbesince is never seen on Bigelovia, nor the not less abundant smaller luteola on Ver- besina. And when we come to look at the Perdita spp. of the Gutierreziay they average still smaller than those of the Bigelovia. I am fortunate in being able to present some figures of the flow- ers of some of the Perdita Compositfe, drawn by Miss Mae Gilmore under the supervision of Professor E. O. Wooton. As they are all on the same scale, (diam. x 5) the reader will be able to form his own conclusions by studying them in connection with the facts above cited. " The honey ... in Compositse is secreted by a ring surrounding 1896.] NATURAL SCIENCES OF PHILADELPHIA. 41 the style at the base of a narrow tubular corolla, and as it accu- mulates it rises up into the wider part of the corolla where it is ac- cessible to the most short-lipped insects, and where the anthers shelter it from rain." — (Hermann Miiller). In the Blgelovia, Aster and Solidago the tube is seen to be narrow, permitting the rapid rise of the nectar, and probably preventing the insertion of the tongue of large bees. Hence, these flowers are visited only by the smaller species of Perdita, with other small Apidse and Andrenidse. In Verbesina and Helianthns the tube is wider, doubtless permitting the larger bees to readily insert their tongues ; but it it is narrower at the neck than Blgelovia or Solidago, preventing small insects from so readily thrusting their heads inward to stretch for the nectar. The wider tube also may prevent the nectar from rising so far, while in Helianthus there is a large bulb to contain it. Solidago canadensis is commonly cultivated in gardens in Europe and there H. Miiller mentions only flies as visiting it (Fertilization of Flowers, p. 321), though he gives a further reference to a paper which 1 have not seen. With us, as has been shown, it is native and visited by several bees. THE NATURE OP SPECIFIC DIFFERENCES. It is a commonplace observation that specific characters are of all kinds, and may be either strongly marked or diflScult to discern. A very small amount of study teaches us that there is no essential difference between those characters called specific and those called' varietal ; in fact, the very same kind of difference which marks species in one group, may only mark varieties or mutations in another. Thus we come to see that the essential distinctions between species are physiological, the morphological ones being only valid for diagnostic purposes just s© far as they happen te* coincide with the physiological. There are even what I have termed " physiological species," i. e.^ species separated only by habit ; not at all, so far as we can judge,. by structure, or if at all, in only a very slight degree. I have else- where cited examples of this kind in Coccidge, but in Hymeoopterai we find many instances in which the tangible characters are reducedl to a minimum. Thus, Schmiedeknecht cites the case of Bomhus: silvarxnn var. $ nigrescens Perez, a submelanic mountain form^ which is only to be separated from B. pratorum by an examination of the genitalia. Among the European Sphecodes also, a study o£ 4 42 PROCEEDINGS OF THE ACADEMY OF [1896. microscopical characters has led to a remarkable increase in the number of recognized species. Only the other day, I received a new part of Marshall's Monograph of British Braconida?, in which the following paragraph is sufficiently significant : — " Nearly a dozen species [of Asj)ilota] have been indicated or described ; tiieir inconstant characters render precise definition ex- tremely difficult, and tabulation almost impossible. . . . Accident has brought to light some facts relative to one species, nervosa Hal., from which it appears that the varieties mentioned by that author [Haliday] belong almost certainly to several distinct species. The fascicornis Hal., requires to be elucidated in a similar way, for the capture and examination of isolated examples of unknown ori- gin, lead to very uncertain results." (Tr. Ent. Soc. Lond., 1895, p. 375). Now in Perdita precisely the same state of afiairs occurs, and it will thus be found that while certain species (e. g., crotonis, luteola) are very easily recognized, some others (e. g., bakerce, verbesmce) are almost as well to be called races or varieties as species. In the opinion of the writer, we have indeed the process of evolution going on under our eyes, the puzzling forms being those which have only lately segregated themselves, and have not yet developed striking peculiarities. Take for example bakerce, the closest ally of the Cleome species zebrata. It does not appear to diflTer more from zebrata than the mutations of the latter do from one another, and in the female is practically identical with it so far as outward signs go. But the S bakerce has a slight but constant difference in its wider supraclypeal mark, and it also differs in its genitalia. These differences would never have been noticed, in all probability, had not bakerce been observed to differ in its habits from zebrata, to frequent not the Cleome, but Golden-rod. In fact, the similarity is so great that Mr. Fox, after seeing specimens, expressed the opinion that bakerce was a synonym of zebrata. Another case, not less perplexing, is found in the albipennis-ver- besince-lepachiclis series. The males of this series, placed in a row, readily separate into those which have narrow yellow bands on the abdomen and those which have not. Those with the bands separate into a series with the flagellum orange, and one with it blackish, and it is seen that the former are from Verbesina, the latter from Helian- thus. 1896,] NATURAL SCIENCES OF PHILADELPHIA. 43 Now the females of this series (that of lepachidis being unknown) separate at once into those with broad distinct yellow abdominal bands, and those with the abdomen only spotted. The former are from HeManthus (rarely from Verhesina), the latter very abundant on Verhesina. But now we find, to our surprise, that some of the males with yellow on the abdomen belong to the spotted females, and come from Verhesina ; while others (with the dark flagellum) belong to the well banded Helianthus females. Further than this, other males without the yellow belong to other well banded Helian- thus females from a different locality. Thus among the Helianthus forms (alhipennis) the females from two localities (La Junta and Las Cruces) are hardly at all different, while their males are decidedly different ; and the male of the Las Cruces form more resembles the $ of verhesince, which is common on Verhesina in the same locality. But the Las Cruces males differ from verhesince in the color of the flagellum ; while the La Junta males, differing from verhesince in the abdomen, resemble it in the antennae ! The difficulty is still further increased by the occurrence of individual varieties presenting other combinations of the "specific" characters. In such a case as this we should be hopelessly adrift without bio- logical observations. There is no apparent reason why the varia- tions in clypeal markings should not be just as " specific" as those in the color of the flagellum, or (as in lepachidis) in the color of the head and thorax. Mr. Fox, after examining a series, concludes that we do not know the $ of alhipennis, and that my alhipennis $ , verhesina' and lejmchidis are all varieties of hyalina. But all this is contradicted by actual observation of the insects on the flow- ers. The characters which I have used occur uniformly in series from the same flowers, except in the case of widely separated local- ities, where they are still uniform for a given flower in a given locality. There will be very rarely an individual proper to one flower found on another, as one or two helianthi on Verhesina, but such excep- tions do not vitiate the general rule. Some characters, as the differ- ence in clypeal markings, belong especially to no one of these series, and hence have no specific value. If, as believed, evolution is in progress among the species of Per- dita, we are naturally led to seek for evidence of natural selection. In some cases, as of the yellow lideola, heata and marcialis, all on yellow flowers, we note at once the utility of the peculiarity ; and when we see the yellow predaceous bug Phymata also on the flow- 44 PROCEEDINGS OF THE ACADEMY OF [1896. ers, the whole matter seems clear. Yet it must be confessed that on Verbesina the yellow beata is extremely rare, while the dark verbe- since abounds. The face-markings, so distinctive of species, differ greatly as a rule in the sexes, and in most species are very constant. There is every probability that they serve as recognition marks ; and it is here significant that when they are very variable, as in 9 zebrata, there is no other species of Perdita on the same flowers that could be confused with the varying one. The species appear to be all single brooded, but the great resem- blance between the vernal numerata and the late summer bigelovice, suggested the possibility of double-brooded seasonally dimojphic species. The strongest fact, however, that militates against this idea is that there are so many more late summer and autumn spe- cies than vernal ones, while the eastern odomaculata is represented by no congener at all in the spring. Another question arose as to the possibility of dimorphism in the males of some species ; references to this matter, which deserves further study, will be found under the species concerned. It will be observed that the grouping of the species is arbitary, those being associated which the student is likely to meet with on the same flowers, or in the same part of the country. This was done because it was felt that no natural arrangement could yet be arrived at, and a purely artificial one, based solely on considerations of con- venience, was better than one which might give a false idea of rela- tionships. The difficulty arises in many cases from the so-called " kaleidoscopic " characters, the possession of which by two species does not necessarily imply descent from an ancestor exhibiting them. Thus hiteola and beata are colored alike in almost every detail (except the black on the pleura of beata), and are extremely diflfer- ent from any other Perdita. But beata in its size and hairy meso- thorax approaches the albipeunis group and departs widely from hdeola. The character of armed cheeks has already been referred to, and several others might be cited. How strangely the several "specific" characters may appear or disappear, is shown well in the series of alblpennis and verbesince. There is, however, one natural group, that of texana and latioVy which is very distinct and may ultimately be regarded as forming a distinct genus. F. Smith's generic name Macrotera has been used for texana, but perhaps incorrectly. 1896.] NATURAL SCIENCES OF PHILADELPHIA. 45 Summing up, the writer has to express the opinion that variations in Perdita certainly do not occur indefinitely in all directions, but that they do occur independently, so that the several species differ from one another hardly soliuich in absolute characters, as in the various combinations presented of similar or identical characters Furthermore, it is apparent that the earliest distinctions between species are at least often of a very subtle character, so that the work- ings of natural selection during the actual process of segregation are anything but easy to observe. And this need not surprise us when we reflect that among ourselves constitutional characters, not easily identified by any coincident structural features, play so large a part in determining our ability to reach manhood and beget off- spring. ARTIFICIAL KEY. (Note. — The numbers before the specific names coincide with the numbers of the same in the descriptive portion.) Entirely yellow, with no conspicuous markings 1 Yellow or orange, with dark markings 3 Head and thorax dark 5 1. 8 mm. long, mesothorax pubescent, pleura with a black patch 63 beata $ About 4 mm. long, head very large, cheeks armed 15 larrece $ Over 5 mm. long, head ordinary, cheeks unarmed, meso- thorax not pubescent 2 2. Antennae dark above, a black line before the eyes, 55 hiteola 9 Antennse not dark, a black dot before the eyes . 55 luleola S 3. Extremely small, cheeks armed, mesothorax mostly green, 16 'inarcialis $ Not so small, vertex with a black band from eye to eye, thorax with black markings 4 4. Size 6 mm., head very large, abdomen without distinct bands 34 cephalotes $ Size 4i mm., head not very large, abdomen with distinct bands 35 puiietosignata $ 5. Abdomen orange, or orange-brown, or ferruginous; not banded, unless at base 6 Abdomen dark brown, or black, or spotted, or banded . . 13 6. Head large, abdomen short and broad, ferruginous, mar- ginal cell obliquely truncate, mandibles bidentate ... 7 Not so 8 46 PROCEEDINGS OF THE ACADEMY OF [1896. 7. Head brown, thorax black 1 texana $ Head and thorax dark green 2 latior $ 8. Cheeks toothed beneath, legs entirely yellow . 14 pulchriov $ Cheeks unarmed , 9 9. Face all dark 10 Face partly pale 11 10. Nervures colorless, abdomen orange .... 54 semicrocea 2 Nervures fuscous, abdomen dark testaceous, 32 halictoides ? Nervures ferruginous, abdomen ferruginous . . 33 hicolor $ 11. The pale color confined to clypeus and triangular marks at side of face 20 chamcesarachce 9 Face all light below antenure ; length 3? mm 12 12. Area between eyes and ocelli smooth and shining likemeso- thorax,2d segment of abdomen with a dark band, vertex and mesothorax not blue 54 semicrocea S Area between eyes and ocelli di.stinctly granular, much duller than the shining mesothorax, 2d segment of abdo- men without a band, vertex and mesothorax dark blue, 20 cham(esarachce $ 13. Clypeus entirely dark 14 Clypeus not entirely dark 24 14. Abdomen piceous with yellow spots or dots, legs with yellow markings 15 Abdomen not spotted ](> 15. Length about 6 mm., abdomen with only 4 pale dots . . 26 var. punctata 9 Length about 5 mm., abdomen with 6 pale yellow spots or blotches 26 sexmnculata 9 16. Abdomen black with pale yellowish bands 17 Abdomen not banded 20 Abdomen dark brown, with a short white band on 2d seg- ment; size very small, less than 4 mm. . 41 cladothricis 9 Abdomen testaceous with suffused bands, mesothorax smooth, shiny 6 ventralis 9 17. Stigma brownish, mesothorax hairy, size larger, 7 mm. or over 18 Stigma entirely pallid, mesothorax practically nude, size smaller, not over 6 mm 19 18. Nervures almost colorless 22 sp}iceralce(e 9 Nervures dark brown 22 y.alticola 9 1896.] NATURAL SCIENCES OF PHILADELPHIA. 47 19. Anterior femora mostly black, abdomen with heavy dark bands 12 mentzelice 9 Anterior femora entirely pale, abdomen with evanescent bands 13 pallid'wr 9 20. Head and thorax piceous, marginal cell obliquely truncate, abdomen ovate, size rather large 1 texana 9 Thorax black except the green metathorax ; head green, front feneous 53 (eneifrons 9 Thorax black except the blue metathorax ; head blue ; a yellow spot on each side of clypeus ... 18 semmerulea 9 Head and thorax green 21 21. Females 22 Males, size small, nervures and stigma testaceous, fore tibise yellow in front 4 arcuaia $ 22. Abdomen broad, mandibles bidentate, marginal cell ob- liquely truncate 2 latior 9 Not so 23 23. Small, about 4? mm. long, nervures brown . . 52 phymatiz 9 Larger, nervures nearly colorless 68 v. nigrior 9 24. Face below level of antenn?e all yellow or white, except clypeal dots in some. Males 25 Face below level of antennae not all pale 43 25. Face below antenna; white 2(i Face below antenme yellow 28 26. Last three segments of abdomen rufous, the other banded 19 crotonis. Abdomen yellowish-white, banded, face below antennre pel- lucid white, first 4 legs all dull white except a dark streak on middle tibiae 50 pellucida. Abdomen dark brown with white m"arkings 27 27. Abdomen with about 6 white marks, or fewer yellowish spots 42 pectidis. Abdomen with two more or less developed w'hite bands, 41 cladothricis. 28. Legs black with a little yellowish 25 affinis. Anterior and middle femora marked with black, cheeks unarmed . . . . 29 Anterior femora all yellow, the 4 anterior tibite not all yel- low 33 First 4 legs all yellow, or at least not marked with black or brown 34 48 PROCEEDINGS OF THE ACADEMY OF [1896. 29. Nervures pallid 22 sphceralcece. Nervures dark 30 30. Face and disc of mesothorax nearly bare, face below anteu- iise bright yellow 31 Face and disc of mesothorax hairy 32 31. Very small, abdomen yellow with pale suffused brown bands 43 biparticeps. Larger, abdomen dark with clean-cut interrupted light bands 27 redan gulata. 32. Head broader than long, distal band on 2d abdominal seg- ment broadly continued to lateral margin, dog-earmarks with more or less of a dark border below . 22 v. alticola. Head round, distal band of 2d abdominal segment failing some distance before lateral margin .... 38 hirsuta. 33. Face all yellow (except the anteorbital spots) up to middle ocellus 29 hdeiceps. Face not all yellow up to middle ocellus . . 49 maculipes. 34. Legs entirely orange-rufous, abdomen black, nervures brown 21 Joxi. Legs not orange-rufous, abdomen banded 35 So. The yellow extending above antenna in median line ... 36 The yellow not extending above antennae in median line . 41 36. The yellow extending above across the face 37 The yellow extending above only at sides and middle line . 39 37. Larger, about 5 mm. long, face-markings resembling ^» 76. Anterior legs entirely yellow, mesothorax dull, sides of face broadly yellow up to level of antennoe, then for a short way suddenly very narrowly 27 rectangulata 9 Anterior legs partly black 77 77. The black bands of abdomen not united on lateral margin, anterior tibiae all yellow, lateral pale triangle of face coming to a point above, face-markings lemon-yellow . . 8 zonalis 9 The black bands of abdomen more or less united on lateral margin, anterior tibire with a black mark behind .... 78 78. Lateral triangle of face obliquely truncate above ; a bluer species 48 bigelovice. 9 var. Lateral triangle of face coming to a point above, but nar- rower than in zonalis, face-markings pallid ; a greener spe- cies 79 79. Supraclypeal mark broad, notched in middle . 24 bakerce 9 Supraclypeal mark narrower, or reduced to two spots . . 23 zebrata 9 80. Female, flagellum only pale testaceous beneath 25 affinis 9 var. Males 81 81. Flagellum dark; species of eastern U. S. . 11 odomaculata. Flagellum mostly yellow ; species of Lower California . . . 67 sparsa. 82. Head large, quadrate, face very hairy .... 62 latlceps $ 52 PROCEEDINGS OF THE ACADEMY OF [1896. Head ordinary, face not so hairy ... 57 asteris 9 var. 83. Abdomen black or dark brown, without pale marks ... 84 Abdomen not banded, but with yellow marks 86 Abdomen distinctly banded 87 84. Cheeks armed, head large, clypeus with a narrow median line and broad anterior border yellow, two yellow spots above clypeus 60 grandiceps $ Cheeks unarmed, clypeus all pale except the usual dots . . 85 85. Lateral corners of clypeus reaching base of mandibles, mar- ginal cell shorter 3 californica $ Lateral corners of clypeus not reaching base of mandibles, marginal cell longer 61 crassiceps $ 86. The yellow abdominal marks oblique, dog-ear marks rep- resented by dots only 9 nevadensis 9 The yellow abdominal marks small and straight . 46 tarda S 87. Males 88 Females 92 ^^. Cheeks armed 6 ventralis. Cheeks unarmed 89 89. Mesothorax granular, abdominal bands without lateral bulgings on proximal margin, face-markings deep yellow, 22 sjyhoiralcece var. Mesothorax smooth and shining 90 90. Middle and posterior femora yellow, without black patches, abdominal bands regular, though with sublateral bulg- ings on proximal margins, marginal cell longer, 30 duhia S Middle and posterior femora with black spots or patches, marginal cell shorter 91 91. Siipraclypeal mark very little broader than long, 23 zebrata $ Supraclypeal mark nearly twice as broad as long .... 24 hakerce $ 92. Nervures colorless ; pale stripe along anterior orbits not extending to level of middle ocellus .... 40 salicis. Nervures dark ; pale stripe along anterior orbits extending to level of middle ocellus 36 exclamans. Species of Texas and Mexico, ivitli the mandibles bifid at tips, the head large, the digma subobsolete, the abdomen broad, rufous in the S , black or piceous in the 9 • 1. Perdita texana (Cr.) Cr., Cat. Hym., 1887, p. 296. 9 Macrotera texana Cr., Tr. Am. Ent. Soc, 1878, p. 70. (Hab., Texas). cf Macrotera me