i HARVARD UNIVERSITY Library of the Museum of Comparative Zoology BULLK/riN''"^ OF THE MUSEUM OF COMPAKATIVE ZOOLOGY IIAllVAUl) rXIVKHSlTV VOL. 131 CAMBRIDGE, MASS., U.S.A. 19()4 The Cosmos Press, Inc Cambridge, Mass., U. S. A. CONTENTS I'AOE No. 1. — American Si'iders of tiik Okms Episiinis (Araneae: Theridiidae). By Herbert W. Levi. :\ran'li. lf)f)4 ' 1 No. 2. — Fossil Mammals from the Lower Pliocene of Fish Lake Valley, Nevada. By John B. Clark, Mary R. Dawson and Albert E. Wood. Mareh, 1964 27 No. ■]. — American Spiders of the Genus I'iKnoucidia (Araneae : Thkridiidak). By IIerl)ert W. Levi. April li)(54 6.') No. 4. — The Braincase of the Paleozoic Elasmobranch Tamiohatis. By Alfi-ed Sherwood Komer. (1 Plate.) April "PKU 87 No. 5. — The Taxonomic Status of Hepiaxudon and Dental Ontogeny in Elasnwdontoniys and Am- hlyrhiza (Kodentia: Caviomorfiia). By Clayton E. Ray. May, 1964 107 No. 6. — The Skeleton of the Lower Carboniferous Labyrinthodont FJiolidogaster pisciformis. By Alfred Sherwood Romer. (1 Plate.) May, 1964 . 129 No. 7. — Early Evolution of the Dissorophid Amphib- ians. By Robert L. Carroll. (2 Plates.) Juiu". 1964 Til No. 8. — The Genus Mioatlx na (Araneae, Araneidae) IN the West Indies. By Artbur M. ('bickeriiiF THE (iKXlS i:i'L'()2. In addition to tlie many similar, minute species, tliere aic a number of larger ones, most tj^uite distinct in structure and also of rare occurrence. Tiie gen- eric placement of these larger species is often uncertain l)ecaus(' of their greater divei-sity in appearance. The study of AmiM'ican Episiinis was made possible tlii-ough the help of numerons colleagues who loaned collections and per- mitted me to examine types. 1 would like to acknowledge witli thanks the loan of specimens fi'om the following collections: Museum National (rilistoii-e Xatnrelle. |*ai-is (.MXIlXi. by Prof. M. Vachon and .1. F. .le/.rMpicI ; the American .Museum of Natural History (AMXII) by \)v. W. -1. Certsdi: the j'.ritish Museum (Natural History) (UMXII) by .Air. 1). .1. Clark. .Mi-. K. H. Hyatt, Mr. E. Browning and Dr. (J. Owen Evans; the personal collection of Prof. A. .M. ( 'hickcrini:' now housed in the Museum of Comparative Zoology: and personal collection of Mrs. D. Frizzell (Dr. II. Exline) ; the Califoi-nia .\cademy of Sciences (CAS) by Mrs. Friz/ell and Dr. K. S. K'<,sx; the histitnl Hoyal des Sci(Mices Naturelh^s dc r.elgi(pic ilS.XP. i h\ \)y. .\. Collar! and Mr. -J. Kekenhosch ; the Scnckcnbcri:- .Museum (SMF) by Dr. O. Kraus; the Xatui-al History .Museum. Stock- holm, by Dr. L. Brnndin ; the Xaturhistoi-isches Museum. N'ienna. by Dr. M. P>eiei-. and specimens from .Miss I!. Zai)fe i.Mi's. C. Mann). I am grateful to Vv. Chr\santhus for checking' tln' lal- iuization of specific names. The examination of types in Kuro- pean museums was made ])ossible by a Xational Science Founda- tion (Irant (G-4317). the completion of the i-evision by a grant fi-om the National Institutes of Health ( Ai-()l!»44). KlMsixrs Latreille /•;/*/.v(/M/.s' I.;itrcillc, lSii!», Ceiicra (•rust.-ifciinini rt I iiscrtdriiiii, 4: :'.71. Type spcL-ics l)y nioiiotypy /■.■. Innicains l.iit rcillc. ISdii, of Kun.iH'. 4 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY Carapace often with a pair of horns between anterior and posterior median eyes. Lenses of lateral and posterior median eyes often on tubercles, with silvery and sometimes reddish pig- ment. Chelicerae small with a tooth or teeth on anterior margin, sometimes without teeth. First legs longest. Abdomen usually modified with humps, tubercles, and sometimes with small nip- ples, often light-colored with gray marks, streaks and sometimes white pigment. The smaller species have less pigment than larger ones. Colulus replaced by two setae. Palpus extremely complex, all structures proliferated, large, connected by large haematodocha. Distril)iiti(iii of Kjiisimis cognat an, iryfliropliflialvuis, tiipiciis, saJobreiusis, iiinii iniihis, a iiiocitKs. LEVI: ami:hi(a.\ i;nsiNus 5 Spet'ics of EpisitiKs ;irc I'ouiid in ail pai'ls of tlic world, al- though most oeciii- ill wanner i-cyioiis. The (list ril)iit ion ol" tlic coninioiiost iVnierican species is illustrated by the iiiap. Episiiuis has luaiiy speeies in tropical Aiiiei-ica. !^^()st species are siiiall with little |iiL;iricnt, llie abdomen is siibl i-ian(Hi. pi. 10. tig. 124, 9 . Female hohitype from IJrazil in the Xaturhistorisehes Museum. Vienna, e.xamined. is a feuude E. fridicatus Tjatreill(\ a EurojMnm species. Most likely the locality is in error. In the keys, "Fig." capitalized refers to this paper, "fig." in lower case, to the pre\ious paper ( Le\'i. llio.l, .lour. Xew York Ent. Soc, 62: 65-90). Key to mall' Episl)n(s l;i. Total leiifi'tli groater tliaii L'.fi inin fcaraii.Mcc more tliaii 1.0 iimi wide) o 111. Tcital leiigtli less than '2.^) nun (caraiJaco 'ess than 0.9 mm wide) .5 2a. Length of palpal tibia aliout eqnals that of cyniliiiim. 3 21). Length of palpal tibia less than two-thirds that of cynibium 4 3a. Conductor (at distal mosal tip) with hook (lOnf), fig. S) ; Te.xas to Ppi-^ cofjiiaiu.i 3b. Conductor without sucli hook (Fig. 8) ; eastern Brazil rccifensis 4a. Embolu,s ba.se hidden by tcgulum (1955, fig. 4); southeastern United States amoenus 4b. Embolus base visible in ventral view (Pig. 15) ; Chile iypinui ."a. Total length greater than 1.8 mm ; filiform portion of embolus of palpus with two bends, S-shaped (1955, fig. 13; Fig. 4) 6 5b. Total length less than 1.7 mm; filiform portion of palpus evenly curved ' 6a. Diameter of anterior median eyes more than three times that of other eyes; conductor as in Figure 4; Cuba, Hispaniola praiiosus 61). Diameter of anterior median eyes less than twice that of other eves; conductor as in 1955, figure 13; Panama to Guianas hruneoviritiis 7a. Conductor ti])i>ed with an ectally directed spine (Fig. 78); Trinidad to eastern Brazil salobrcnsis b BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 71). Comlurtor otherwise 8 8a. Pnlpnl tibia equal in length or longer tlian evniliiuni 9 81). Pali)al tibia le.ss than two-thirds cymliial lengtli 11 9a. Embolus filament a relatively thick, short structure (Fig. o7 ) ; soutli- eastern Brazil , himvnijii y 9b. Emliolus filament a relatively fine, long structure; Central America 10 l(ta. Distal margin of embolus liase abnost transverse to long axis of cym- biuni : distal portion of l:)ulb witli an t'ctal iii'ojection (Fig. .50): Nicaragua ospus lOli. Distal nmrgin of cmljolus base not transverse, ectal inojection lack- ing (19-5.5, fig. 1-i) ; Panama ptuianicnsis: 11a. Lengtli of palpal tibia less than one-third cyml)ial length; palpal bulli tipped liy two transpai'ent projections (1955, fig. 11) ; Mexico to Panama colima 111). Ijcngth of paljial tibia about equal to or more than half length of cymbium ; Inillial tip otherwise 1- 12a. Bulbal tip with a sclerotized elbowed piece (1955, fig. 12) ; Bahama Isls., Jamaica nadlcri 12b. Bulbal tip otherwise 1.3 13a. Distal end of palpal bulli with an ectal pointing hook (Fig. 45) ; Panama raticus 13b. Distal end otherwise 14 14a. Embolus base with a mesally directed lobe above filiform portion (Figs. 90-93) ; Panama to Bolivia erjithropliflialmux 14b. Eni1)olus base without a mesally directed lobe above liase of filiform portion (1955, figs. 5, 7) ; Mexico 15 15a. Ectal sclerotized margin of conductor widest on distal end (1955, fig. 5) juarezi 151i. Ectal sclerotized margin of conductor widest on iiroximal end (1955, fig. 7) chiapensii Key to female Episiuus la. Abdomen with a large dorsal extension, liigher than long or wide (Fig. 24) ; southeastern Brazil tercsopolis II). Abdomen otherwise with at most a median dorsal tubercle 2 2a. Abdomen widest anteriorly 3 2]j. Abdomen widest in middle or posteriorly 4 3a. Abdomen with a median dorsal tuliercle (Fig. 23) ; Venezuela iniplexiis 31). Abdomen without median dorsal tubercle (Fig. 11); Panama crnanns 4a. Aljdomen suljspherical with a median dorsal tubercle (Figs. 30, 31); Peru malnrliin us 4b. Abdouu'n otherwise 5 5a. Abdoiiieu longer tlian wide; total length more tliau 2.4 mm fi 51). Ahdomeii as wide as long or wider than long or if longer than wide, total length less than 2.2 mm 10 LEVI: AMKHICAX Kl'lSIXUS 7 (i;i. Alidoiiicii with ;i dorsal ilistiiict white foliimi pat tern hordercd by lilack (1955, fig. 34); Panama to (iiiiaiias hnnieoviridis lili. Abdomen otherwise 7 7a. Ki)i{jyninii with an anterior stderotized raised kncdi (Fifj. Ki) ; alido- ineu jiointiMl aiiterioily (Kig. 14); Chile tj/piriis 7li. i^piiiynuiii otherwise; alidoinen truncate anteriorly 8 Sa. Epigyniun with a slight dei)ression liordered anteriorly and around sides (1955, fig. L'l ) ; total length more than 4.4 mm; Texas to Central Peru rofinntn.s Slj. Hpigynum depression not liordi'red anteriorly; total lengtli less than 4.5 mm; eastern IT. S. west to .\laliama, Cuiia, Ilispaiiiolu . . '.' '.•a. I'^pigynum depression anterioi- to seminal receptacles (Figs. \, '1,; Culia, Hispaniola f/ratio-sufi '.til. Iljiigynum depression posteiior to seminal ii'ceptacles (1955, fig. 17); eastern U. S., ^laryland to Alabama (iniornus Ilia. .Xbdomen subspherical, widest in middle (Figs. IS, 20 i or diamond shaped (Fig. 7) ; total length 4.0 mm or more 11 Kill. Aliilomen sulitriangulai', widest lu'ar postei'ior; total lengtli less thaii o.O mm 12 11a. Abdomen with liumjis on middle of sides (Fig. 7 ) ; e])igynum with a scape (Fig. i;ia. Abdcimen with dorsal tubercles or iiijiples 14 1Mb. AbdonuMi without dorsal tubercles or nipples 19 14a. .\bdomen with a single median dorsal iiipi)le (Fig. 37) 15 14b. Abdomen with several dorsal nijiples (Figs. 27, 34, 40) li! 15a. Duet winding twice around seminal reeeptacdes (1955, fig. 31); -Mexico jitarczi I5li. Duct winding once around seminal rei cjilacdes (Fig. 38); Panama pavamnisis Ilia. Abi- gynum otherwise 17 17a. Hpigynum with a distinct transverse lip (Fig. 36); T'anama pjinis 17b. Epigynum otherwise 1'*^ ISa. Connecting ducts wound once around seminal recejitacdes (Fig. 41); Peru mni/oha nihil 18b. Connecting ducts probably very short (1955, figs. 20, 27); Hispani- ola (lominit'iis 0 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 19a. Epigyniim depression with a median septum (Fig. 44) ; ducts short, opening into middle of ectal side of seminal receptacles (Fig. 43); Costa Eica, Panama vaticus 19b. Epigynum and ducts otherwise 20 20a. Epigynum openings in two dark spots anterior to seminal receptacles (Figs. 5.5, 56) ; southeastern Brazil bicorniger 20b. Epigynum openings otherwise 21 21a. Openings in a corner of a depression; area anterior and Ijetween sem- inal receptacles sclerotized (Fig. 66) ; eastern Brazil to Paraguay . . . nehulosus 21b. Openings usually indistinct; area between seminal receptacles some- times sclerotized but not anteriorly 22 22a. Seminal receptacles long and S-shaped (Figs. 73, 74) ; Trinidad to eastern Brazil salohrensis 22b. Seminal receptacles not S-shaped 23 23a. Duct coiling twice around receptacles (1955, fig. 31) ; Mexico . juarezi 23b. Ducts coiling at most once around receptacles 24 24a. Seminal receptacles spherical (1955, fig. 29); Bahama Isls., Jamaica 7iadle)'i 24b. Seminal receptacles ovoid or longer than wide ; Central America and South America 25 25a. Epigynum with a median anterior dark spot (Fig. 49) ; connecting ducts not coiled completely around seminal receptacles (Fig. 48) ; Nicaragua aspus 25b. Epigynum without median dark spot; connecting ducts coiled at least once around seminal receptacles 26 26a. Connecting ducts entering openings from posterior (Figs. 58-61) ; Venezuela ^urlus 26b. Connecting ducts entering openings from side 27 27a. Dorsum of abdomen with a longitudinal dusky band and two cross bands (Fig. 72); median area of epigynum liglit (Fig. 71); Mato Grosso bicruciatus 271). Dorsum of abdomen light, epigynum without such median light area (Figs. 81, 83, 85) ; Panama to Bolivia criitlirophihahniis Episinus immundus (Keyserling), new combination Figures 16-22, Map Theridium immundum Keyserling, 1884, Die Spinnen Amerikas, Theridiidae, 2(1) : 89, pi. 4, fig. 57, 9. Two female syntypes from Le Para [Belem, Para], Brazil, in tlie ^luseum National d'Histoire Naturelle, Paris, ex- amined. Other syntypes come from Pebas, [Loreto], Peru. Theridium hi tuberculatum Keyserling, 1884, op. cit., 2(1 ' : !'2, pi. 4, fig. 60. Juvenile female liolotype from Pevas, Aniazonas, [I'ehas, Loicto, Peru], in the Museum National d'Histoire Naturelle, Paris, examined. NEW SYNONYMY. LEVI: AMERICAN EPISINUS 9 Tliiimoitcs iminundis, — KcyserliiiK, 188G, op. rit., 2(2): 295. ThymoUes hituhcrculatus, — KcyserliiiK, 188(5, op. cit., 2(2): 295. Thymoiles higihbosus Eoewer, 1951, Abliandl. iiatunviss. Vcrein Biciiien, 32: 504. New name for Thymoites hituberculatus Keyserlinfj, thouRlit preoccupied by Hypomma bititherculatns Wider. NEW SYNOXYMy. Description. Carapace rich brown with sonic silvery i-cddisli pigment between lateral eyes. Sternniii lijz'iit brown willi dark brown spots; spots on sides emjiliasize the lobes {F\\r:. ID). Leys banded rich dark brown on lihue. 24 Jan. 1954 (E. S. Ross. A. E. Michelbacher. CAS) ; La Picada en el Volcan ()s()i-ii(.. .laii. 1958, 9 (11. /apfe); Rio (ioI-Col. Feb. 1957. S LEVI: AMERICAN ElMSINUS 11 (L. Pcfia, ISXB). Lhinquihui : Carcliuapii. 'J7-12S 1<\'1». lit.')!, ?, i (L. IVfia, ISNB). Cliilo( : Cliaitrii. (i Fd.. 1!):)4 (L IVfia ISXB). Episinus bruneoviridis (Mcllo-Lcitao) FaiditHs bruncoviriclis Mcllo-Lcitao, 194.S, An. Ac-ad. Brasilcira ("icin'., I'd; 156, figs. 4, 5, 9. Female holotypo from Cane Grove, British (uiiana in the British Museum, examined. Episinus bruneoviridis, — Levi, 1955, Jour. New Vork Knf. So... iVl: "0, figs. 13, 19, 20, 34, 9, (P^'ig. 23) may be diagnostic. Episinus dominicus Levi Episinus dominicus Levi, 1955, Jour. New York Ent. Soi-., 62: 77, figs. L'6. •21, 3s, 9. Female holotype from Valle de Polo, Dominicnn tJeiiulilic, in the American Museum of Natural History. Distrihution. Known from only the type specimen from His- paniola. 16 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY Episinus unitus sp. n. Figures 27-29 Type. Female holotype, from 3 km south of Unity Valley, St. Ann Parish, Jamaica, 9 Dec. 1954 (A. M. Nacller), in the American Museum of Natural History. The specific name is an arbitrar}' combination of letters. Description. Carapace gray with a lighter V-shaped mark; eyes reddish. Sternum graj' . Legs yellow-white. Abdomen gray with some white spots on sides; venter lighter with a reddish cast. Anterior median eyes larger than others, less than one diameter apart, almost touching laterals. Posterior median eyes one diameter aj^art, touching laterals. Horns between eyes. Abdomen with seven dorsal nipples in a transverse row (Fig. 27). Total length 1.4 mm. Carapace 0.65 mm long, 0.60 mm wide. First femur, 1.17 mm; patella and tibia, 1.27 mm; meta- tarsus, 1.17 mm. Second patella and tibia, 0.80 mm; third, 0.52 mm ; fourth, 0.91 mm. Diagnosis. Like E. moyohamha, E. pyrus and E. dominicus, the abdomen has numerous nipples (Fig. 27). The small distinct median depression of the epigynum (Fig. 29) and the shape of the seminal receptacles (Fig. 28) separate the species. Record. One ? and juvenile paratypes collected with type. Episinus moyobamba sp. n. Figures 40-42 Type. Female holotype from Moyobamba, San Martin, Peru, 20 Dec. 1946 ^J. C. Pallister), in the American Museum of Nat- ural History. The specific name is a noun in apposition after the type locality. Description. Carapace, sternum, legs yellow-white. Reddish around eyes. Ends of fourth femora and patellae slightly red- dish. Abdomen with irregular gray marks, reddish around nip- ples, on each lateral projection and on posterior. Anterior me- dian eyes larger than otliers, their diameter apart, almost touch- ing laterals. Posterior median eyes three-quarters diameter apart, one-quarter from laterals. A pair of horns between eyes. Abdomen snbtriangular with numerous dorsal nipples (Fig. 40). Total length 1.3 mm. Carapace 0.52 mm long. First femur, 1.00 mm. Second patella and tibia, 0.70 nnn ; third, 0.47 mm: fourtli, 0.75 mm. (The specimen described is damaged.) LEVI: AMEKICAX KIMSINUS 17 Diagnosis. Like the related E. dominicus the abdomen lias nip- ples on the dorsum (Pig. 40). The eonneetinp: ducts wind once around the seminal receptacles (Fig. 41), wliilc tliose of E. dominicus are shorter and do not wind around. Episinus pyrus sp. n. Figures M-'M) Type. Female liolotype from Suininil, Panama Canal Zone, 16-17 August 1950 (A. M. Chickering), in the Museum of Com- parative Zoology. The specific name is an arbitrary combination of letters. Description. Carapace yellow-white with a bright red median band (Fig. 34). Sternum yellow-white, legs yellow-white with distal end of femora and patellae dusky. Dorsum of abdomen mottled black but area around each nipple and lateral extension bright red (Fig. 34). A red patch on each side of abdomen. \'enter yellow-white. Carapace with two horns between anterior median eyes. Anterior median eyes slightly larger than poste- rior medians, much larger tlian laterals, laterals on tubercles. Anterior median eyes three-quarters diameter apart. Posterior median eyes one diameter apart, their radius from laterals. Total length 1.2 mm. Carapace 0.52 mm long, 0.52 mm wide. First femur, 0.96 nnn ; patella and tibia, 1.08 mm ; metatarsus, 0.71 nun ; tarsus, 0.47 nun. Second patella and til)ia. 0.62 mm ; third. 0.47 mm; fourth, 0.78 mm. DicKjnosis. Like E. dotiii)iicus and E. iiioyohdiiiha tlie abdo- men has dorsal nipples (Fig. 34). The transverse lip of the epigynum (Fig. 36) separates E. pyrus from these related spe- cies. The connecting ducts are very short (Fig. 35). Records. Panama Canal Zone: Sunnnit Park, Dec. 1957, 9 paratype (A. M. Chickering) ; Summit, 21-29 July 1950, 9 para- type (A. M. Chickering). Episinits colima Levi Kpi.''. 45). The epifjynuni depression has a median posterior septnin (Fig. 44) and the connecting ducts are very short (Fig. 43), unlike other Central American species. The abdomen lacks dorsal nip- ples (Fig. 47). Records. Costa Rica: San Isidro del General, (iOO-l^OO m, S (D. Rounds). Panama Canal Zone: Forest licserve, 4-() .Inly, 1939, 9 paratype (A. M. Chiekering). Episinus aspus sp. n. Figures 48-51 Type. Male holotype from ^lusawas, Waspuc River, Nica- ragua, 30 Sept. 1955 (B. Malkin), in the American Museum of Natural Histor3^ The specific name is an arbitrary combination of letters. Description. Carapace yellow-white, dusky on sides. Eye re- gion reddish. Sternum gray. Legs yellow-white. Abdomen red- dish and black around border of dorsum ; center of dorsum with white pigment in male, without pigment in female ; venter reddish in female, dusky in male. Anterior median eyes seem- ingly larger than others, about one-third their diameter apart. Posterior median eyes less than one diameter apart, touching laterals. Pigment around base of lenses makes it difficult to see their exact shape. The females have horns between eyes, but these are absent in males. Abdomen subtriangular (Fig. 51), smooth, lacking nipples. Total length of female 2.2 mm. Cara- pace 0.71 mm long, 0.62 mm wide. First femur, 1.50 nnii ; pa- tella and tibia, 1.42 mm; metatarsus, 1.36 mm; tarsus. O.GO nnn. Second patella and tibia, 0.85 mm; third, 0.58 mm; fourth, 1.17 mm. Total length of male 1.5 mm. Carapace 0.62 mm long, 0.55 mm wide. First femur, 1.48 mm; patella and tibia, 1.59 mm; metatarsus, 1.32 mm. Second patella and tibia, 0.85 nun; thii-d, 0.65 mm; fourth, 1.17 mm. Diagnosis. The distal margin of embolus l)ase is almost at right angles to the long axis of the palpus (Fig. 50), while it is diagonal in the related E. panamensis. The median anterior dark spot of the epigynum (Fig. 49) and the longer seminal receptacles and shorter connecting ducts (Fig. 48) distinguish females from E. panamensis. Record. One 9 paratype collect(Hl with holotype. 20 BULLETIN: MUSEUM OP COMPARATIVE ZOOLOCA' Episinus bimucronatus (Simon), new coml)ination Figures 52-54 Spliyrotinus himncronaius Simon, 189-i, Histoire Naturelle des Araignees, 1: 551, nomen nudum; 1894, Ann. ent. Soc. France, 64: 144. Female holo- type from San Esteban, [Aragua], Venezuela, in the Museum National d 'Histoire Naturelle, Paris, examined. Description. Carapace yellow-white with silvery pigment be- tween eyes and dark pigment behind anterior median eyes. Sternum, legs whitish-yellow. Abdomen with white pigment spots on dorsum and posterior (Fig. 54). No horns in eye re- gion. Diameter of anterior median eyes equal to radius of other eyes. Lateral eyes on tubercles. Anterior median eyes one and one-half diameters apart, almost touching laterals. Posterior median eyes one-third diameter apart, one-quarter diameter from laterals. Abdomen wider than long with a median anterior hump and two posteriorly directed humps (Fig. 54). Some stronger setae on dorsum of distal end of patellae and some on tibiae. Total length 1.4 mm. Carapace 0.54 mm long, 0.44 mm wide. First femur, 1.04 mm; patella and tibia, 1.00 mm; meta- tarsus, 0.84 mm ; tarsus, 0.40 mm. Second patella and tibia, 0.68 mm ; third, 0.46 mm ; fourth, 0.76 mm. Episinus bicorniger (Simon), new coml)ination Figures 55-57 Theridium hicorne Keyserling, 1891, Die Spinncn Amerikas, Brasilianisclio Spinnen, 3: 193, pi. 7, fig. 140, 9, $. Male and female syntypes from Serra Vermelha, [Est. Eio de Janeiro], Brazil, in the British Museum, examined. Not T. hicorne Wider. Janulus bieornigera Simon, 1894, Histoire Xnturelle des Araignees, 1: .IIT. New name for T. hicorne Keyserling. Abdomen subtriangular as related species. Total length of female 2.2 mm. Total length of male 1.7 mm. Episinus ji'arezi Levi Episinus juarczi Levi, 19.15, Jour. New York Ent. Soc, G2 : 74, figs. 5, 6, 30, 31, 42, 43, 5, $. Male holotype from Tamaulipas, :Mexico, in tlie American Museum of Natural History. Distrihiitio'u. Tamaulipas, San Luis Potosi to Oaxaca, Mexieo. Episinus chiapensis Levi Episinus chiapensis Levi, 1955, Jour. New York Ent. Soc, 02 : 76, fig. 7, $ . Male holotype from Las Ruinas de Palenque, Chiapas, ^Mexico, in the American Museum of Natural History. Distribution. Known only from Chiapas, Mexico. LEVI: AMERICAN EI'ISINUS 21 Efisinis nadleri Levi Episinus nadleri Levi, 1955, Jour. New York Eiit. Soc, ni2 : 77, fifjs. 12, 28, 29, 37, 9, 6. Female holotype from Soiitli P.imiiii, Ualiama Isliiiids, in the American Museum of Natural Histoiv. Disiribi(tio)t. Bahaiiui Islands and Jamaica. Additional Record. •Jamaica: Tlic (ii-cal Morass, 25 Mai-cli 1955, 6 (A. M. Nadler, AMXIl). Episinus nebulosus (Simon), new comliination Figures 64-68 Janulus nchiilosns Simon, 1895, Ann. Soc-. ent. France, 64: 1.35. Female holotype from Serra de Communaty, Prov. Pernambuco, Brazil, in the Museum National d'Histoire Naturelle, Paris, examined. Janulus ffcrmaini Simon, 1895, ihid., 64: 136. Female holotype from Para- guay in the Museum National d'Histoire Naturelle, Paris, examined. NEW SYNONYMY. Note. Female holotype of ./. nebulosus has a label indicating that it comes from Sa. Communaty, an unknown location placed by Simon at times in the neighboring state of Ceara. Description. Carapace with sides brownish, darker than mid- dle. Sternum, legs yellow-brown ; ends of segments slightly darker. Abdomen with scattered fine black spots and some white pigment spots anteriorly on dorsum, between humps and around sides. Venter of abdomen gray, darker on sides than in middle. Two horns in eye region. Lateral and posterior eyes on tubercles. Abdomen about as wide as long (Fig. 67). Epigynum openings distinct (Fig. 66) ; two duct loops in ventral view if cleared and one loop visible in dorsal view of female genitalia (Figs. 64, 65). Total length 2.8 mm. Carapace 0.82 mm long, 0.74 mm wade. First femur, 1.40 mm; patella and til)ia, 1.62 mm; metatarsus, 1.36 mm; tarsus, 0.36 mm. Second patella and tibia, 0.86 mm; third, 0.64 mm; fourth, 1.12 mm. The holotype of J. germaini is a younger adult female still showing a dorsal abdominal pattern (Fig. 68). The epigynum and internal genitalia are like those of the holotype of J. )u'hu- losus. Episinus bicruciatits (Simon), new combination Figures 69-72 Janulus hicruciatus Simon, 1895, Ann. Soc. ent. France, 64: 136. Female holotype from Mato Grosso, Brazil, in the :Mus('um National d'Histoire Naturelle, Paris, examined. 22 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY Description. The whole specimen j^ellow-white except some pigment behind anterior median eyes and silvery around other eyes. Abdomen with indistinct longitudinal gray band having two cross bands (Fig. 72), a black mark on venter above pedicel, a distinct round black spot on posterior side of each lateral tu- bercle and a white pigment line on each side of spinnerets out- side of which is a black mark. Horns between eyes large ; lat- eral and posterior median eyes on tubercles. Abdomen subtri- angular with tubercles more distinct from ventral view. Total length 2.6 mm. Carapace 0.76 mm long, 0.68 mm wide. First femur, 1.52 mm; patella and tibia, 1.60 mm; metatarsus, 1.50 mm ; tarsus, 0.54 mm. Second patella and tibia, 0.84 mm ; third, 0.62 mm; fourth, 1.14 mm. Episinus salobrensis (Simon), new combination Figures 73-78, Map Janulus salohrensis Simon, 1895, Aim. Soe. ent. France, 64: 135. Two fe- male syntypes from Salobro [near Vargito on old maps], Bahia, Brazil, in the Museum National d 'Histoire Naturelle, Paris, examined. Episinus erytlirophihalmus, — Levi, 1955, Jour. New York Ent. Soc, 62: 74, figs. 24, 25, .36. Not E. erythroplithalmus (Simon). Description. The two type specimens are almost colorless yel- lowish, the only pigment being silvery behind eyes ; sides of carapace sliglitly darker than middle. Posterior sides of abdo- men slightly reddish, some small white pigment spots, and a larger white spot on each side of spinnerets. Horns between eyes small ; lenses of lateral and posterior median eyes on tubercles. Abdo- men subtriangular (Fig. 77). Total length of one female syn- type 2.0 mm. Carapace 0.80 mm long, 0.70 mm wide. Legs broken off. Figures 73-75 and 77 were prepared from a syntype. The female has been described previously (Levi, 1955). The anterior lateral margins of the oval depression of the epigynum are more or less sclerotized. Although the specimen previously described had red eyes, no others seen have red ])igment in the eye region. Only fragments of males collected with females were available. Records. Lesser Antilles. Trinidad: Simla near Arima, 12 Dec. 1954, ? ; 28 Dec. 1954, 9 (A. M. Nadler, AMNH) ; Port of Spain, 1913, 9 (R. Thaxter). Britisli Guinna: Kuyuwdni Landing, Kuyuwini River, 20 Nov. 1937, 9 . $ fragments (W. G. Hassler, AMNH). Brazil. Pernamhuco: Recife (SMF). LEVI: AMEKICAX KIMSIXUS 23 EpISINUS ZURLl'S sp. 11. Fi<>'iires 58-63 Type. Male holotype from Venezuela (E. Simon) in llie Museum National d'llistoire Naturelle, Paris (no. 13029). Tlie name is an arbitrary combination of letters. Note. Altliough it is poor praetiee to describe new species witliout accurate locality data, 1 liave done so here liecanse a niiiiibci- of specimens, both male and fcnialt', ai-c a\ailabl('. Also, it is known that Simon, who collected tlie six'ciniens, travelled in only a small region of Venezuela : from the Caracas vicinity to Tovar, Arapua, to Valencia, Puerto Cabello and San Esteban, Carabobo. The specimens were in the Paris collections, mixed up with specimens of E. eryihrophfJialinuH and labelled as such. Description. Carapace yellow-white, some pigment behind an- terior median eyes, silvery between other eyes, sternum, legs yellow-white. Abdomen posteriorly and sides gray, center of dorsum with white pigment spots and .some gray pigment ; ven- ter light gray, darker toward sides. Carapace witii relatively small horns between eyes (Fig. 62). Anterior median eyes much larger than lenses of other eyes, which are on tubercles. Ab- domen without dorsal nipples (Fig. 62). Total length of fe- males 2.5 mm. Carapace 0.68 mm long, 0.64 mm wide. First femur, 1.56 mm; patella and tibia, 1.44 mm; metatarsus, 0.86 mm; tarsus, 0.42 mm. Second patella and tibia, 0.84 mm; third, 0.60 mm; fourth, 1.04 mm. Total length of male 1.6 mm. Cara- pace 0.62 mm long, 0.56 mm wide. First femur, 1.52 mm ; pa- tella and til)ia, 1.56 mm; metatarsus, 1.36 mm; tarsus, 0.56 mm. Second patella and tibia, 0.84 mm; third, 0.62 mm; fourth, 1.08 mm. DiaejnosiH. The connecting ducts lead posteriorly from the openings (Figs. 58-61) unlike the similar E. erythrophtlKilmvx. The transverse line between the openings is sometimes more anterior, sometimes more posterior, in different specimens (Figs. 60, 61). The males are distinguished from E. erythrophthalmns by the basal flare of the conductor, which projects ventrally, is sclerotized, and has small teeth on the margin (Fig. 63). Records. Male and female paraty]ies collected with holotype. Episinus ERYTiiROPirriiAi..Mrs (Simon) Figures 79-93, Map Januhi.t erythrophthaJmus Simon, 189-4, t'roc. Zool. Soc. Londori, p. 525. IMale and female syntypes from St. Vincent Island, Lesser Antilles, in the British Museum, examined. Not E. erythrnphthalmvfi, — Levi, 1955. 24 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY Description. Specimens from Panama. Carapace j^ellowish with dusky border and dusky patches on each side. Sternum white. Legs yellowish with dusky marks. Dorsum of abdomen black behind and on sides ; light central area with white spots (Figs. 86, 89). Venter with epigastric area gray and black patches on sides that are extensions of the lateral and posterior dorsal black areas. Female generally lighter and less distinctly marked than male ; white spots more numerous and smaller, but also usually having the four dark marks on venter. Two horns between eyes. Anterior median eyes much larger than others. Posterior and lateral eyes on tubercles. Total length of female 2.00 mm. Carapace 0.62 mm long, 0.62 mm wide. First femur, 1.32 mm; patella and tibia, 1.44 mm; metatarsus, 1.28 mm; tar- sus, 0.44 mm. Second patella and tibia, 0.78 mm ; third, 0.54 mm ; fourth, 0.98 mm. Total length of male 1.5 mm. Carapace 0.59 mm long, 0.55 mm wide. First femur, 1.32 mm; patella and tibia, 1.47 mm; metatarsus, 1.28 mm; tarsus, 0.47 mm. Second patella and tibia, 1.02 mm; third, 0.52 mm; fourth 1.04 mm. Figures 80, 81, 90 were prepared from the syntypes. Note. This species, apparently widespread and relatively common, is quite variable. At first it was thought that the speci- mens coming from Panama belong to three species ; l)ut, on care- ful comparison, they were all found to have the same propor- tions and only superficial differences in the epigynum and pal- pus. The seminal receptacles and more sclerotized parts of the palpus are similar. The differences seem to be due to different degrees of transparency of the epigynum and the position of the anterior transverse sclerotized piece (Figs. 81, 83, 85). The transparent palpal sclerites seem to be in slightly different posi- tions in each individual (Figs. 90-93). Distrihution. Panama to Bolivia. Records. Panama. Arraijan (A. M. Chickering) ; 8 km S of El Valle (A. M. Chickering). Panama Canal Zone. Forest Re- serve ; Madden Dam ; Chilibre ; Summit ; Balboa ; 3 km N of Paraiso (all A. M. Chickering). Lesser Antilles. Tohago Isl. (P. H. Johnson, BMNII). Triinelad: Simla near Arima (A. M. Nadler, AMNH). Piarco (A. M. Nadler, AMNH). Venezuela. 9, $ (E. Simon, MNHN). /)/.^^ Ffrf.; Caracas. 1887-1888, $ (E. Simon, MNHN). Arao !» a ai M bD OJ fin 15 S ;^ =H o M & P^. f^ o M ' cc 2 '•^-^ 'S oi s tH s IjEV I : A M i:k 1 ( ■ A x i: I • I s I \ rs BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY f^ 'ft s _bjD J5 ^ ^. w •rt C4 ci H CO o -^ ^ ^ fe^ Ki fe; fac bcs^ ^S mT: ^ ^ ^ Ph P^-p, Phs S^ Ph Ph Ph LEVI: AMERICAN EIMSINUS r^m ^-x/ ':'t . %■' N«? A^ (.."felfW .^ifH^lSSA fi BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY ':? ct & ^ ^ f^ ^ fei f^ fc^' i.Kvi : a.mi:ki(ax iii'isixrs €D A !l# '®=ii BULLETIN : MUSEUM OF COMPARATR'E ZOOLOGY M bX) 'E 'ft H H s o ■73 CD ^ g bJ3 s bjD tuD 5 s a . O t3 ^ B Ol •-i t> =4-1 1 O 02 O) f^ a •-3 w fl &X) 03 bC bD ^ "^ t^ ^ Cd (VI 4i S -^ S S ft 03 S o O) Oi f^ f^ ^- g K «2 S "^ a 2 5 rn' ■" ^ ft ^ I s 00 0) ■<*i o as _aj lO '3 to 13 •o "rt C3 c s t» OJ C/3 dJ tc a* M Ph be p^ bJ5 Ph S S S cc § S g ^ ? -§ Ah .2 ^ S S "^ « 00 no CO o3 be LEVI: A.MKHK A\ Kl'lsixns BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY ^ o CO OO '^ 00 "^ -2~ ^ a3 00 t- c to ^ X cc r 1 ^ p^ Ci ;^ f^ i-H ?: f** Ci 'S _&J3 „ P^ Ci s W OO CO O )n 00 ^- 00 ^ r^ o ?> co' op 00 01 C ^•~ 00 00 i % cu G ^ fe) > xn CO Oj o ^ o c: CO bb Cw I-H s S 00 S o" 6jD 00 LKVi : ami:hi(a.\ i:iMsi.\rs Bulletin of the Museum of Comparative Zoology HARVARD UNIVERSITY Vol. 181, No. 2 FOSSIL MAMMALS FROM THE LOWER PLIOOENE OF FISH LAKE VALLEY, NEVADA By John B. Clark, Mary R. Dawson aiul Albert E. Wood CAMBRIDGE, MASS., U.S.A. PRINTED FOR THE MUSEUM March 30, 1964 Publications Issued by or in Connection WITH THE MUSEUM OP COMPARATIVE ZOOLOGY AT HARVARD COLLEGE Bulletin (octavo) 1863 ■ — The current volume is Vol. 131. Breviora (octavo) 1952 — No. 199 is current. Memoirs (quarto) 1864-1938 — Publication was terminated with \^ol. 55. JoHNSONiA (quarto) 1941 — A publication of the Department of Mollusks. Vol. 4, no. 41 is current. Occasional Papers of the Department op Mollusks (octavo) 1945 — Vol. 2, no. 28 is current. Proceedings of the New England Zoological Club (octavo) 1899-1948 — Published in connection with the Museum. Publication terminated with Vol. 24. The continuing publications are issued at irregular intervals in num- bers which may be purchased separately. Prices and lists may be obtained from the Publications Office of the Museum of Comparative Zoologv, Cambridge 38, IMassachusetts. Of the Peters ' ' Check List of Birds of the World, ' ' volumes 1, 4 and 6 are out of print ; volumes 3, 5, 7, 9, and 15 are sold by the Museum, and future volumes Avill be published under Museum auspices. The Proceedings of the First International Symposium on Natural Mammalian Hibernation edited by C. P. Lyman and A. R. Dawe is available as volume 124 of the Museum of Comparative Zoology Bul- letin. Published in 1960, it consists of 26 papers and a general discus- sion, totalling 550 pages. Price $3.00 paper back. $4.50 cloth bound. Publications of the Boston Society of Natural History The I'cmaining stock of the scientific periodicals of the Boston Society of Natural Ilistorv has been transferred to the Museum of Comparative Zoology for distribution. Prices for individual numbers may be had upon request. Bulletin of the Museum of Comparative Zoology HARVARD UNIVERSITY Vol. 131, No. 2 FOSSIL iMAMMALS FROM THE LOWER PLIOCENE OF FISH LAKE VALLEY, NEVADA By John B. Clark, Mary R. Dawsox and Albert E. Wood CAMBRIDGE, MASS., U.S.A. PRINTED FOR THE MUSEUM March, 1964 Bull. Mus. Coiiii). Zoo)., Ilarvnr.l riiiv., 131 (2) : 27-63, ^rnrcli, 1964 No. 2 — Fossil Mammals from the Lower Pliocene of Fish Lake Valley, Nevada By John I>. ("lark/ .Makv II. Dawson- a.n'd Ai.bkkt E. Wooo^ INTRODUCTION The material on which this study is based was collected by Wood, in 1935, from Hall's locality A (1930c, pi. 37, fi». 1) in the early Pliocene Fish Lake Valk^y bods, Esmeralda Formation, seven miles north of Arlemoiit, Nevada. The material formed the basis for tlie unpublished Master's thesis, submitted to Amherst College, by Clark. In subsequent years it has proven impossible for him to complete the paper for publication, and the material has now been reworked by Dawson and Wood. Wood has brought up to date and revised Clark's manuscript for the rodents, and Dawson has done the same for the other forms. The authors are grateful to Di's. J. T. Gregory, Donald Savage and R. A. Stirton for the loan of specimens ; to Mrs. Katherine M. Reed and Drs. Claude Hibbard and Peter Robinson for dis- cussions ; and to Mrs. Frances W. Wood for critical reading and other assistance in preparation of the manuscript. Figures 6 and 7, B, C and D were drawn by Dr. Florence D. Wood. The material was collected while Wood was Cutting Traveling Fellow in Columbia University. The study has been assisted by the Dorothy Bridgman Atkinson Fellowship of the American Asso- ciation of University Women awarded to Dawson, and by grants from the National Science Foundation and the Marsh Fund of the National Academy of Sciences to Wood. Abbreviations used are : M.C.Z., Museum of Comparative Zoology; S.D.S.M., South Dakota School of Mines and Technology; U. Cal., University of California Museum of Paleontology. We are grateful to the Museum of Comparative Zoology for undertaking the publication of this paper. 1 Biology Department, Marietta Collego, Maiiotta, Ohio. 2 Carnegie Museum, Pittsbur^'li, rennsylvaiiia. 3 r.iology Department, Amherst College, Amherst, Massachusetts. 30 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY Order INSECTIVORA Family TALPIDAE DoMNiNoiDES cf. BiPARENsis Greeii, 1956 Figure 1 Material: M.C.Z. Nos. 17887, incomplete left lower jaw having Ml, M2-M3 (broken), alveoli of P4 ; 17888, incomplete left lower jaw having Mo, alveoli of P4, Mj, M3 ; 17889, left M2 (broken). In size (Table 1) and in most general characteristics these specimens resemble the type and only previously reported speci- men of Domninoides riparejisis, S.D.S.M. No. 53170, from the Clarendonian Wolf Creek faunule of South Dakota (Green, 1956, pp. 152-154). Compared to teeth in the type specimen, M.C.Z. No. 17889 is less worn, M.C.Z. No. 17887 is slightly more worn, and M.C.Z. No. 17888 is much more w^orn. Fig. 1. Domninoides cf. riparen.tis. T.ateial view of left lower jaw, M.C.Z. No. 17887, X 9. The most distinct difference from the type specimen is exhibited by M.C.Z. No. 17887 (Fig. 1), which has on Mj a small but dis- tinct anterior cingulum that connects to the anterolingual cuspule. The anterior wall of M^ in the type is smoothly convex, lacking a cingulum. Another difference appears on M3 in M.C.Z. No. 17887, which has an anterior cingulum that is more reduced buceally than in S.D.S.M. No. 53170. Also, in the type specimen the metastylid of Mj is larger than that of Mo, whereas in M.C.Z. No. 17887 the metastylid of Mo is prominent and a distinct metastylid is absent on Mj. CLARK, DAWSON, WOOD: FOSSIL MAMMALS OF NEVADA 'M The taxonomie !si<;nitieaiicc' o£ these dift'erenees is questionable in light of the few available specimens. Possibly the variation in the anterior wall of jM^ is a matter of individual diversity. Somewhat similar individual variation has been rei)orted in another fossil talpid, Mesoscalops scopclotcnws, in which there is "variable development of a small anterior einpulum, wliieh appears in the majority of specimens" (Reed, 1960, p. 4). That the size of the anterior cingulum may vary with wear in the Fish Lake Valley talpid is shown by the fact that the cingulum on the well worn M2 of M.C.Z. No. 17888 is narrower than that of M.C.Z. No. 17887. Similarly, stage of wear could account for the difference between the type and M.C.Z. No. 17887 in the cingulum of M3. Since wear and individual variation are perhaps responsible for the differences between the Fish Lake Valley talpid and the type of D. riparensis, a definite specific assignment should wait until more specimens allow better estimation of the range of variation in either population. Variation that can be recognized as individual is exhibited by the two jaws from Fish Lake Valley, which differ from one an- other in the position of the two mental foramina. In both jaws, as in the type, the anterior foramen is below P;. . One specimen, M.C.Z.No. 17888, resembles the type in having the more posterior foramen in line with the posterior wall of the alveolus of P4, whereas ]\LC.Z. No. 17887 has the posterior foramen farther forward, in line with tlie middle of P4. Table 1 Measurements (in niillinieteis) of Domninoidrs ef. riparcufsis M.C.Z. No. 17 887 M.C.Z. No. 17888 JNT] length ca. 2.3 width tiigonid 1.4 — Avidth talonid 1.7 — Mo length — 2.4 width trigonid 1.7 1.7 width talonid — 1.6 alveolar length Mi-M;i ca. 6.5 6.1 outside depth jaw, at middle of Mi 2.2 2.1 32 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY Order ?INSECTIVORA Figure 2 A toothless fragment of a left lower jaw, M.C.Z. No. 17900 (Fig. 2), represents an unidentifiable species of small mammal. The alveoli of the penultimate tooth, wdth the anterior wall broken away, and of the last tooth indicate that the penultimate tooth was somewhat larger than the last. The alveolus of the last tooth is 1.4 mm long. The alveolus for the root of the trigonid of the last tooth is set obliquely to the long axis of the jaw, directed anterolingually to posterobuecally, and is longer on the lingual side. The alveolus for the root of the corresponding tal- onid is longer anteroposteriorly and narrOAver transversely than that of the trigonid. The wall between the two alveoli of the last tooth has an indistinct, shallow groove dorsally, and that between the two alveoli of the penultimate tooth is more distinctly grooved. The deep masseteric fossa is bounded anteriorly by a rounded ridge. Lingually the surface of the jaw is essentially smooth ; a dental foramen occurs near the posterior edge of the incomplete specimen. Below the last tooth, the jaw is 1.5 mm deep. Fig. 2. ?Insectivore. Lateral view of left lower jaw fragment, INI.C.Z. No. 17900, X 8. Compared to other known members of the Fish Lake Valley fauna, M.C.Z. No. 17900 shows closest resemblance to Mystiptcrus vespertilio, the type and only reported specimen of which is a broken fragment of a jaw with Mo (IT. Cal. No. 29604). In both there is a deep masseteric fossa, and lingually both jaw frag- ments are essentially smooth. The toothless jaw is a little larger than the type of Mystipterus vespertilio and seems to have the anterior border of the ascending ramus relatively farther from the last tooth. The specimens are too incomplete to allow more than partial comparisons, and M.C.Z. No. 17900 is regarded as indeterminate. CLARK, DAWSON, WOOD: FOSSIL MAMMALS OF NEVADA 33 In the course of tliese comparisons the question arose again of tlie taxonomic assignment of Mystipterus, originally described as a vespertilionid bat and compared with Minioi)tcrus by Hall (1930a, p. 319). Ke-examination of the characters of Mysiipterus and of the differences from Miniopterus led Patterson and Mc- Grew (1937, pp. 256-257) to assign the former to the insectivore family Soricidae. The features of Mystiptcrus cited by Patterson and McGrew as characteristic of soricids occur in some othei- insectivores as well. The deep masseteric fossa, for exam]ilo, is found also in Xycfitlifriu))}, Micro ptcrnodus (Matthew, 1909. pi. 51, fig. 1), and a geolabidine insectivore, cf. Myolcstcs dasypclix (McKenna, 1960, p. 147). The combination of characters known in Mystipterus may not preclude reference to the Sorieidae, but at the same time they do not seem to make such a reference the only assignment possible. It would seem necessary to have speci- mens of Mystiptcrus in addition to the rather inadequate type in order to clarify the taxonomic position of the genus. Order LAGOMORPHA Family OCIIOTONIDAE HeSPEROLAGOMYS"' new genus Type species: Hcspcrolagomys fjalhreathi n. sp. Diagnosis: Cheek teeth hypsodont but rooted; occlusal surface of P^'-Mi with persistent crescentic valley, hypostria extending almost to crescent, and anteroloph transversely wider than posteroloph ; P^ with buccal fold between trigonid and talonid, anterointernal groove in trigonid, lingual wall short anteroposter- iorly ; trigonid of P4-M2 wider and shorter than talonid, talonid with anterior protrusion directed toward trigonid, and postero- lophid present in early stage of wear ; large mental foramen below P3, smaller mental foramina anterior to P3 and in line between M1-M2 ; lower teeth include M1-M3 ; size near that of Orcolagus nevadensis; tooth measurements a.s given in Table 2. HeSPEROLAGOMYS GALBREATIir'' U. sp. Figures 3-4 Type: M.C.Z. No. 17890, incomplete right lower jaw with broken incisor, P3-M2, and alveolus of M3. 4 Pr()iii (Jrci'k : hcspcros — wi'st : Iih/ok — Iimpc; iii/m — iiidusc. o For Dr. E. ('. Galbreath in r('(oj,'niticiii ol" his wurk (ni fossil lagoiiioriihs. 34 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY Hypodigm: Type; M.C.Z. Nos. 17891, fragmentary left lower jaw with P3-M2 ; 17892, fragmentary left lower jaw with talonid of P4 to M2 ; 17893-17894, upper incisors ; 17895-17899, isolated upper cheek teeth; 7651-7652, isolated lower cheek teeth. Prob- ably referable, U. Cal. No. 29633, upper deciduous premolar. Diagnosis: As for the genus. Description: The skull, with the exception of a maxillary frag- ment, is unknown, and the upper dentition is represented by isolated teeth only. The anterior upper incisor has a longitudinal groove slightly medial of center on its anterior surface. The part of the incisor medial to the groove protrudes farther anter- iorly than does the lateral part. Of the upper cheek teeth, P- and P^ are not known, but P^ and probably JVP are represented. Unilateral hypsodonty is exhibited by these teeth, which are convex lingually (Fig. 3 A, C, D). Two small buccal roots and a larger lingual root are present on the knowai upper cheek teeth. Pig. 3. Hesperolagomys galhreathi, 11. gen., n. sp. Upper rheek teeth, X 9. Probable Ml, M.C.Z. No. 17898; A, anterior view; B, occlusal view. P4, M.C.Z. No. 17896; C, anterior view; D, occlusal view. CLARK, DAWSON, WOOD: FOSSIL MAMMALS OF NEVADA 35 On a worn P^, ^IX'.Z. Xo. ITcSf)."), the anterior lopli is wider than tlie posterioi- h)ph. The pattern on the occlusal surface includes an isolated, cement-filled, creseentie valley in the buccal half of the tooth and a cenient-lilled internal hypostria. The hypostria is directed toward the anterior wall of the crescent and extends almost to its lingual wall. Features of the buccal edge of the occlusal surface cannot be determined due to breakage. Another specimen, M.C.Z. No. 17896 (Fig. :i C, D), seems to be a relatively unworn P^. At the occlusal surface the anterior and j)osterior lophs are nearly equal in width, but farther down the shaft the anterior loph protrudes more medially. A central lobe connects to the buccal wall between two rounded cuspules and extends in a wide V to join the posterior wall of the tooth. Anterior, lingual, and posterolingual to the central lobe is the cement-filled depression that forms the creseentie valley of the more worn tooth. Posterobuecal to the lobe is a second cement- filled depression. The buccal exits of these depressions are blocked by the buccal cuspules. The internal hypostria crosses about one-third of the occlusal surface. A worn tooth, M.C.Z. No. 17898 (Fig. 3 A, B), probably is a molar. In this specimen the anterior loph protrudes farther lingually than the posterior loph ; the complete width of the anterior loph is not shown, owing to its broken lingual wall. The creseentie valley divides anterobuccally into tw'O distinet parts around a transversely elongated cuspule. The aiiterobuccal part of the vallej' seems to be better developed than in M.C.Z. No. 17895, a P"* in an approximately comparable stage of w^ear. The probable molar lacks the posterobuecal cuspule and is reduced posterobuecall.y in comparison with M.C.Z. No. 1781)6, although valid comparisons with the latter are limited by differences in stage of wear. Interpretation of M.C.Z. No. 17898 as a molar is supported by comparisons w'ith Amphilagus fontannesi, a late Miocene oehotonid in which M^ reseml^les this probable molar and P'l is more similar to M.C.Z. No. 17896. The closer resemblance of M.C.Z. No. 17898 to M^ than to M^ of A. fontannesi suggests that it may be the anterior molar, since M^ is more reduced posteriorly in A. fontannesi (Forsyth Major, 1899, pi. 36, figs. 6 of M-, 7 of Ml, 8 of P^). An isolated upper tooth, U. Cal. No. 29633, was tentatively identified as Entoptychusf sp. (Hall, 1930c, p. 296) but was subsequently recognized as a deciduous premolar of a lagomorph (Wood, 1936c, p. 25). The tooth is smaller than the permanent 36 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY upper teeth of Hesperolagoruys, but probably represents this ochotonid rather than the much larger leporid of the Fish Lake Valley fauna. The lower jaw and dentition are more adequately represented than the upper. The ventral border of the horizontal ramus (Fig. 4 B) is essentially straight below the cheek teeth and curves up, below the diastema. The jaw is slightly deeper below the posterior than below the anterior cheek teeth. The shape of the jaw is more similar to that in Titanomys and Oreolagus than to that in Ochotona, in which the jaw is deeper below the anterior cheek teeth and has a more concave dorsal border at the diastema. Fig. 4. Hespcrolagomys galhrcaflti, ii. gen., ii. sp. Right lower ^aw with P;rM2, type, M.C.Z. No. 17890, X 6- A, oeelnsal view of cheek teeth; B, lateral view. On the lateral surface of the jaw are several mental foramina ; the largest of these is in line with the talonid of P3 and below mid-depth of the jaw. A smaller foramen occurs anterior to P3, above mid-depth, and a depression with two small foramina is situated in a line between Mi and Mo and lower than the anterior foramina. This disposition of mental foramina, with the middle foramen the largest, differentiates Hespcrolagomys from other known ochotonids. In Desrnatolagus vetustus, D. gohiensis, and SinolagomyH (Bohlin, 1942, pp. 62-63), anterior and posterior CLARK, DAWSON. WOOD: FOSSIL MAMMALS OF NEVADA 37 mental loramina are present. Between them there occurs in some specimens another small foramen or foramina approximately in the position of the large foramen in TlesperoJagomys. Presence of a series of mental foramina seems to be primitive for lago- morphs. Different ochotonids retain and emphasize different foramina of this series. Hesperolagonnjs retains a primitive series, with emphasis on the middle foramen. Another variant on these foramina in an ocliolonid is seen in KcnjjalafjfJinijs of the Miocene of Africa, in which the two main mental foramina (Maelnnes, 1953, p. 10) seem to correspond to the middle and posterior foramina of Hcspcrolagninys. In Ochotona the single mental foramen, probably representing the posterior foi-amen of Hesperulagomys, is situated below M2. The shaft of the incisor extends approximately to a line below the middle of Mj, as indicated by a swelling on the medial surface of the jaw. The lower cheek teeth are hypsodont but rooted. For most of their length the trigonid and talonid of P4-M2 are connected by cement only, but a short distance above tlie roots the dentine of the two columns becomes confluent. An isolated tooth, probably a molar, shows two small rootlets for the trigonid and a single root for the talonid. The alveolar portions of P-; and P4 are relatively straight anteroposteriorly and extend down lateral to the shaft of the incisor. The lateral surface of the jaw swells out over P4, thus giving space for that tooth lateral to the incisor. The alveolar portions of M| and M2 curve posteriorly and in this way avoid interfering with the shaft of the incisor. The most complete lower jaw is the type specimen, M.C.Z. No. 17890 (Fig. 4). On P3 a cement-filled buccal fold crosses about half the occlusal surface and marks the division between ti-igonid and talonid. The trigonid is rounded anterobuceally. Antero- lingually, P3 has a wide, shallow groove with a thin coating of cement. This groove is interpreted here as being in the ti'igonid, and not between trigonid and talonid. The lingual wall of P3 is short anteroposteriorly. The trig'onids of P4-M2 are wider transversely and shorter anteroposteriorly than the corresponding talonids. Each talonid sends forward a narrow protrusion. Enamel is prominent on the external and posterior walls of trigonids and talonids. The alveolus of M3 is rounded buccally and is narrower transversely than that of the talonid of M2. The shape of the alveolus suggests that Mo was probably more rounded and less tapered buccally than is that tooth in Ochotona. 38 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY A young individual of Hesperolagomys is represented by IT. Cal. No. 29626, an incomplete lower jaw with P4-M1 (Hall, 1930c, p. 311 ; the specimen was tentatively identified hy Hall as Sylvilagusl sp.)- Small posterolophids, which would be worn away a short distance down the tooth, occur on the talonids of the two teeth. The limited hypsodonty of Hesperolagomys is illus- trated by this specimen, in which the little worn P4 shows at its base the confluence of the dentine of the columns that occurs just above the roots. Table 2 Measurements (in millimeters) of Hesperolagomys galbreathi M.C.Z. M.C.Z. M.C.Z. No . 17895 No. 17896 No. 17898 P-i pi probably Mi length 1.5 1.5 1.3 width anteroloph — 2.3 2,9 width posteroloph — 2.2 2.5 M.C.Z. No. 17890 type specimen P3 length 1.1 width 1.2 P-i length 1.7 width trigonid 1.9 width talonid 1.4 Ml leugtli 1.6 widtli trigonid 1.8 width talonid 1.4 M2 length 1.6 width trigonid 1.7 width talonid 1.4 alveolar length Ps-Mj 8.1 length P3-M2 5.8 length P4-M2 4.9 inside depth jaw, at middle of Mi 5.3 Hesperolagomys is an ochotonid that retained into the early Pliocene a number of primitive characteristics, among which are the rooted cheek teeth, persistence of folds in the buccal part of the occlusal surface of P^ and j\P, and talonids that are nar- I'ower transversely than the trigonids on P4-M2. Combined with CLARK, DAWSON, WOOD: FOSSIL MAMMALS OF NEVADA '.]9 these primitive characteristics, Hcspcrolagomys exhibits its own peculiar features, including the marked anterior protrusion of the talonids on P4-M0 and the disposition of the mental foramina. Other ochotonids that have been reported from the North American later Tertiary are OrcologKs from the Miocene and Ochotona whicli first appears in the middle Pliocene. Among the characters distinguishing Oreolagus from Hesperolagomys are, in the former, higher crowned cheek teeth, shape and proportions of the lower cheek teeth, in wliich the trigonids and talonids of P4-M2 are more nearly equivalent in width, and absence of M3. Ochotona is distinguished from Hesperolagomys by its more hypsodont cheek teeth, absence of a persistent crescentic valley on P-* and ]\P, more complex folds on P^, and approximately equivalent width of the columns of P4-M2. The presence of Hesperolagomys with its primitive characteristics in the North American early Pliocene seems to be a parallel to the presence oi Amphilagus fonfannesi, an ochotonid likewise having primitive dental features, in the late Miocene of Europe. Unless there has been a reversal of evolution aifecting several characteristics, which seems unlikely, Hesperolagomys was de- rived from a primitive ochotonid. Of known forms, Desniaiolagus, which has rooted cheek teeth and a generally primitive level of development, could be near the ancestry of Hesperolagomys. More specific evidence for such an affinity, other than the merely primitive features, is afforded by the structure of P.3. In Hesperolagomys that tooth has a narrow lingual exposure and an anterointernal groove that seems to be in the trigonid. Desma- tolagus gohiensis of the late Oligocene of Asia has a somewhat similarly shaped P3 in some individuals ; in late stages of wear the anterointernal groove is worn away in that species. An earlier species, D. vetustus of the Mongolian early Oligocene, shows the same general pattern of folding on P3, but the lingual wall is less reduced anteroposteriorly than in D. gohiensis (Burke, 1941, pp. 16-17) and Hesperolagomys. A trigonid of Po, that is divided by an anterior fold, and an internal wall of P3, that becomes reduced in later species, are among the characters distinctive of Burke's " Desmatolagus phylum" (1941, pp. 17, 22). If the folds on P3 in Hesperolagomys have been interpreted correctly, the similar structure of that tooth would seem to indicate affinity with Desmatolagus. Whether Hesperolagomys is clo.ser to Asian species of Desmatolagus or to North American species referred to that genus remains to be determined. 40 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY Family LEPORIDAE Hypolagus fontinalis Dawson, 1958 Material: M.C.Z. Nos. 7640, incomplete left lower jaw with P4-M2 ; 7641, left premaxilla with upper incisors; 7642, isolated teeth ; 7643, postcranial fragments including proximal and distal ends of humerus, astragali, ealcanea, navicular. Hypolagus fontinalis, a previously known member of the Pish Lake Valley fauna (Dawson, 1958, p. 48), is represented by these specimens. Lower cheek teeth agree in size (Table 3) and struc- ture with other specimens of this species. The upper cheek teeth of H. fontinalis were previously un- known. Two folds, of which the lingual is longer, occur on the anterior surface of P-. The internal hypostria crosses somewhat more than half the width of the occlusal surface on P^-M^. The walls of the hypostria are strongly crenulated on P^; on speci- mens that are probably P"* or M^ the walls are less strongly crenulated ; and in a specimen that seems to represent M- the walls are only slightly wavy. Thus, the folding in the walls of the hypostriae decreases posteriorly in the series of molariform teeth. In general structure the upper cheek teeth resemble those of H. vetus, a species averaging larger in size than H. fontinalis. Table 3 Measurements (in millimeters) of Hypolagus foniinalis M.C.Z. No. 7642 M.C.Z. No. 7640 M.C.Z. No. 7643 P2 length width 1.2 2.6 P4 or Ml length width anteroloph width posteroloph 2.3 4.2 4.0 P3 length width trigonid width talonid 2.6 2.0 2.5 P4-M2 length 7.4 astragalus, length proximodistal 10.6 width 5.4 humerus, length proximal end 10.9 CLARK, DAWSON, WOOD: FOSSIL MAMMALS OK NEVADA 41 Tlie posteranial parts are smaller than eorrespoiidinf? parts of //. vctus but suggest similarity to H. vetus in general level of development. Order RODENTIA Family ('K1("HT11)AE COPEMYS AVood M)W Type species: Hesperomys loxodon Cope 1874. Referred species: C. dcntalis (Hall), C. longidens (Hall), C. kfJIoggae (Ploffmeister), and C. esnieralelensis n. sp. Distribution: Late Miocene Barstow and Niobrara River to early Pliocene Fish Lake Valley; Nebraska, New Mexico, Cali- fornia and Nevada. Emended diagnosis: Cricetid in which alternation of buccal and lingual cusps has begun to develop; crowns low; no distinct mesocone or mesoconid, although mesoloph or mesolophid may be well developed ; protoconid and metaconid of Mi unite, after varying amounts of wear, at anterior end of protoconid ; meta- conid of M.).;j at anterior margin of tooth, with anterior cingulum absent or restricted to buccal margin of tooth; paracone of M^ unites with posterior end of protocone and, sometimes, with its anterior end; metacone of M^ unites with posteroloph rather than with hypocone; metacone of M- tending to unite in this manner ; lower incisors broad ; mental foramen l)elow or just in front of Mj ; masseteric fossa prominent, ending below Mj ; deep valley between M.^ and the coronoid process. One of the striking peculiarities of North American Tertiary rodent history is the record of the cricetids. In the middle Oligo- cene, Ewmys is unquestionably the most abundant rodent, and a number of different species have been recognized. Leidymys and Scottimus have developed from a Eumys ancestry. Species of Eumys are known from the Oligocene of the Great Plains (Wood, 1937; Galbreath, 1953) and of Montana (Wood, 1937, p. 262; White, 1954, pp. 410-415). In the early Miocene, two species of Leidymys and Paciculus insolitus are known from the middle John Day (Wood, 1936a). Eumys eliensis, from the equivalent Fort Logan of Montana (Black, 1961c, pp. 7-10), seems to be more closely related to E. hrachyodus of the plains than to the large Montanan species of Eumys described by White (1954). It seems possible that Cotimus (Black, 1961a) may be 42 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY related to Paciculus, known only from the upper teeth (Wood, 1936a, pp. 4-6; Black, 1961c, pp. 10-12). Scottinms kellamorum is a continuation of the Oligocene Scottimus lineage (Black, 1961b). The only described North American cricetids between the early Miocene and the late Pliocene are : Horatiomys montanus (Wood, 1935b, if it is a cricetid), and Pociculus montanus (Black, 1961c) from the Deep River of Montana ; Cotimus alicae from the Flint Creek of Montana (Black, 1961a) ; Miochomys niohrariensis from the Niobrara River (Hoffmeister, 1959) ; and four species of Copemys — C. longidens (Hall) from the late Miocene Barstow of California, G. kdloggae (Hoffmeister) from the late Miocene Niobrara River of Nebraska, C. loxodon (Cope) from the late Miocene or early Pliocene Santa Fe of New Mexico, and C. dentalis (Hall) from the early Pliocene Fish Lake Valle.v. An- other species of Copemys from the Fish Lake Valley is described below. The published record would indicate that the cricetids were nearly absent from the Great Plains area during the Miocene and most of the Pliocene, although they survived and evolved in the intermontane areas farther west. Even at such a semi-inter- montane area as Split Rock there are no cricetids among the thousands of rodent teeth known. The dominant North American Miocene small rodents were the entoptychine geomyids. In the Pliocene, their place seems to have been taken by the heteromyids. The cricetids do not come back into the picture until the end of the Pliocene, when both hesperomyine and microtine forms be- come abundant. Perhaps the invasion of the Old World micro- tines reduced the competing heteromyids, and allowed the native American cricetids to spread eastward once more. The presence of C. kelloggae in Nebraska and of cricetids in the Miocene of Florida (Wood, 1947, p. 491), however, shows that they were not completely absent in the great plains and farther east. The present evidence suggests that the hesperomyines were derived from the eumyines in a manner somewhat similar to that shown in Figure 5, and that the series Eumys — Leidymys — Copemys — Peromyscus is not far from a true phyletic sequence. The citation of Leidymys in the Oligocene is based on the refer- ence to that genus of L. vetus (Wood, 1937, p. 257). Galbreath (1953, p. 72) states that in his opinion Eumys exiguus and Leidymys vetus represent the same species. In this allocation he is followed by Black (1961b, p. 3). However, Leidymys is CLARK, DAWSON, WOOD: FOSSIL MAMMALS OV NEVADA 43 characterized by a well-developed hypocone-like cusp on M-^. In Eumys, includin<>' E. exiguus, this cusp is at most an enlarged cingulnm. Since Leidymijs is presumably derived from Eumys, the transition must have occurred as individual variants. But Eumys exiguus also shows the development of anteroposterior connections between the crests, leading toward Scottimus (Black, 19611), p. 3, transfers it to Scottimus, which is just as reasonable as leaving it in Eumys), and there is no trace of these in the type of Leidymys vetus. The status of tlie Oligocene eumyine rodents UPPER PLIOCENE AND LATER ONYCHOMYS PEROMYSCUS EARLY PLIOCENE 'C.ESMER- C.DENTALIS\ / ALDENSISx LATE MIOCENE COTIMUS \ \ \ \ ^. C.KELLOGGAE \, C.LOX- ODON MIOCHO- MYS C.LONGIDENS V "I COPEMYS MIDDLE MIOCENE PACICULUS \ \ EARLY MIOCENE PACICULUS \ \ SCOTTIMUS \ EUMYS \ LEIDYMYS \ \ ELIENSIS ^^ ^ LATE OLIGOCENE \ / E.BRACHY- ODUS MIDDLE OLIGOCENE SCOTTIMUS /E.BRACHY- EARLY OLIGOCENE / ODUS E. EXIGUUS \ LEIDYMYS VETUS LL_EUMYS / COMPLEX / E.ELE6ANS. Fig. 5. Phylogenctic iL']:itioiishij>s of North Aiiieric-an Tertiary crii-etids. 44 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY will have to remain nebulous until the very extensive collections are studied, so that it will become possible to separate individual variations from specific and generic variants. There is so much variation among North American Oligocene cricetids that all possible later trends seem to be represented within a single population, sometimes even in the material from a single ant hill. Very few if any of the described forms can be considered to be adequately categorized and separated from each other. Cotimus (Black, 1961a, p. 73) is distinct from Copemys. It may represent the hitherto undescribed lower teeth of Paciculus. At any rate, as stated above, it is close to that genus, and not in the line leading to Peromyscus. Hoffmeister (1959, p. 698) has pointed out the similarities of Miochomys to Onyckomys (Fig. 5). The former genus is most probably also derivable from Leidymys. Horatiomys is as isolated as when it was first described (Wood, 1935b, p. 3). Copemys includes several forms at rather diverse levels of development. All the species seem to be evolving in slightly dif- ferent directions, and the data are not adequate at present to determine ancestor-descendant relationships among the group. The alternation of the buccal and lingual cusps and the shifts in the points of attachment of the various cusps and crests are progressive features foreshadowing Peromyscus. Copemys loxodon (Cope) Figures 6-7 II esperomys loxodon Cope, 1874, jj. 148. Eitmys loxodon (Cope). Cope, 1875, p. 993. Peromyscus loxodon (Cope). Hay, 1902, p. 727. Copemys loxodon (Cope). Wood, 1936a, p. 5. The synonymy given here, rather than that cited previously by Wood (1936a, pp. 5-6), is the correct one. Type: U.S.N.M. No. 1204, right lower jaw with Ii and Mj.o ; an isolated right I^ may belong to the same form, and an isolated right I] certainly does not. Hypodigm: Type only. Emended diagnosis: Well developed lingual mesolophids, ex- tending from posterior arm of protoconid to lingual margin of crown and ending in a distinct mesostylid ; posterior cingulum of M2 connecting with buccal rather than lingual margin of liypo- conid; masseteric fossa with everted, overhanging dorsal margin; tooth measurements as given in Table 4. CLARK, DAWSON, WOOD: FOSSIL MAMMALS OF NEVADA 45 X o 46 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY Descri'ptio7i: The masseteric fossa is quite unusual, in its over- hanging dorsal margin (Fig. 6). No suggestion of such a struc- ture is seen in other species referred to this genus, but there is clearly considerable interspecific variability in this respect (Figs. 8E, 9F). The ventral margin of the fossa extends to the ventral border of the angular process, as in C. dentalis. The masseteric knob, at the front of the fossa, lies beneath the middle of Mj, and is more distinct than in C. dentalis, but less so than in C. esmeraldensis. The mental foramen lies just in front of the an- terior root of Mj as in the other species. There is a pronounced groove between M3 and the coronoid process. The latter passes the alveolar border by the middle of M3. Fig. 7. Copcmys loxodon, U.S.N.M. No. 1204, X 10. A, EM1-2; B, medial view of right lower incisor ; C, ventral view of right upper incisor ; D, dorsal view of another right lower incisor with same number. The cheek teeth of the only known specimen of this species are quite distinctive (Fig. 7A), and are farther removed from the Peromyscus pattern than are those of the other members of the genus. As suggested by Wood (1936a, p. 6), the closest relatives of this species seem to be "certain species from the Miocene and CLARK, DAWSON, WOOD: FOSSIL MAMMALS OF NEVADA 47 Plioceiu' of California and Nevada, which have been described as Peroniyscus," and which are liere referred to Copemys. The peculiar position of the posterior cinj^ulum of M2 is just as unique as it seemed in 1936 {op. cit., p. 6), but Hooper's recent study (1957) of tooth variation in Peromyscus shows how much variability can exist within a single living genus, and warns us to be careful about drawing the lines of specific or generic varia- tion too tightly among fossil forms. (The magnification shown for these teeth in Wood, 1936a, fig. 5, is incorrect, that figure being 7.5, rather than 5, times natural size.) The lower incisor (Figs. 6, 7B) is similar to that of other species of the genus. The anterior face is fairly flat. At the tip of the median side, there is an extensive flat area, where there has been interdental wear with the tooth of the opposite side. This is also present on the type of C. dentalis, but all other specimens are too broken to be sure whether this is a generic character, although it probably is. It w'ould probably be associ- ated with a well-developed Transversus mandibulae muscle. The upper incisor associated with this specimen (Fig. 7C) is of the correct size and general shape to belong here, but it cannot with certainty be referred to this form. Another lower incisor (Fig. 7D) is much too small for Copemys, and is too narrow and with too heavy an anterior enamel face to belong to a cricetid. It agrees in size, shape, and shape of the pulp cavity with the incisor of small heteromyids, and presumably is referable to a member of that family. Copemys dentalis (Hall) Figure 8 Peromyscus dentalis Hall, 1930c, p. 306. Type: U. Cal. No. 29635, a lower jaw with lili and Mi_2. Hypodigm: Type, and U. Cal. No. 29636, edentulous right jaw, and U. Cal. No. 29638, left jaw with M1.2. Emended diagnosis: Fossa between M3 and the coronoid proc- ess bears small nutritive foramina; mental foramen below dia- stema as in C. loxodon; anteroconid area of Mi simple as in C. longidens, but larger than in C. loxodon; mesolophid present or absent, and low when present ; no distinct hypoconulid on Mi ; metaconid of M2-3 far forward, eliminating lingual half of anterior cingulum as in C. loxodon; low^er incisor narrow ; tooth measurements as given in Table 4. 48 BULLETIN : MUSEUM OP COMPARATIVE ZOOLOGY Description: The tooth pattern of this species (Pig. 8 A-B) is more Peromyscus-\ike than is that of the genotype. The teeth show the Peromyscus type of alternation of cusps, but the cusps are still less completely integrated with the lophs than in Per- omyscus, warranting the reference of this species to a genus ancestral to Peromyscus, for which Copemys is the best name until a great deal more is known about Miocene and early Plio- cene North American cricetids. Fig. 8. Copemys dentalis. Teeth X 10, jaw X 5. A, U. Cal. No. 29635, RMi-2, type; B, U. Cal. No. 29638, LMi-o; C, U. Cal. No. 29635, type, cross section of right I:, from rear; D, TJ. Cal. No. 29636, cross section of right I], from front; E, lateral view of lower jaw, anterior lialf based on U. Cal. No. 29635, type, and rear half on U. Cal. No. 29636. In Mj , the anteroconid is somewhat larger than in C. loxoclon, and is close to the metaconid. There are distinct ridges running posteriorly from the protoconid, along the buccal margin of the tooth, in all teeth. These are also present on Mj of C. loxoclon (Fig. 7 A), but are less well developed in other species. The mesolophid (or posterior arm of the protoconid) is absent in all teeth except Mi of IT. Cal. No. 29638, where it extends as a faint, low ridge to the buccal margin of the tooth (Pig. SB). The hypoconulid seems poorly developed on M^, but distinct on M2. The incisor has a rounded anterior face with a heavy coat of enamel. It is slightly concave on the medial side of the type (Pig. 8 C) which is not shown in the other specimen (Pig. 8 D), and is probably due to crushing, and, at this level, is certainly not due to interdental wear. CLARK, DAWSON, WOOD: FOSSIL MAMMALS OF NEVADA 49 Tlie jaw is slender, with no su>i'gest ion of a cliin pi'oeess. The mental foramen is below the posterior portion of the diastema. The masseteric fossa is shallower than in other species of the genus, being bounded by faint ridges, especially on tlie dorsal side (Fig. 8 E). The anterior end of the fossa is beneath the middle of Mj. Posteriorly, the ventral border of the fossa ap- proaches the ventral margin of the angle. The base of the incisor, in U. Cal. No. 2!)().'}(), I'oi-ms a knob on the lateral surface of the mandible, at the level of the molar alveoli but well behind them. This knob Is brok'cn through on the specimen. COPEMYS LONGIDENS (Hall) Peromyscus longidens Hall, 19.'501), i). .'515. Peromyscus sp. Hall, 19301), p. 310. Peromyscus sp. Hall, 1930b, p. 31(). All of Hall's specimens seem to be within the limits of one variable species, in which variation is no greater than in living species of Peromyscus (Hooper, 1957). There is a single anteroconid on M^ of the type, as in the previously discussed species. A crest, probably the mesolophid, reaches the lingual margin of the crown in the type. It is much smaller in U. Cal. No. 28503. In U. Cal. No. 28506, the cre.st is complete but its lingual half is very low. The isolated tooth of Hall's first Peromyscus sp. (U. Cal. No. 28517 ; it is Mj, not P4 as Hall stated) is about ten per cent smaller than the type specimen, and is somewhat (but not significantly) narrower than the other material. The isolated M2 of U. Cal. Xo. 28516 is intermediate in size between what would be expected for that of U. Cal. No. 28517 and the rest of the population. There is a faint trace of an anterolingual cingulum on M^ of the type, but it is almost eliminated. The mesolophid is very short on tiiis tooth. The lingual anterior cingulum of M^ is very small. In the type, the entoconid and mesolophid are minute. There is a lingual marginal ridge connecting the metaconid and entoconid. The upper teeth show progressive development of lophs. In Ml of U. Cal. No. 28515 the metaconid unites with the middle of the posterior cingulum. In M-, there is the beginning of this posterior union (not shown in Hall's figure, 1930b, fig. 7 A), but the union between the metacone and hypocone is still i)resent. The mesoloph (or anterior arm of the hypocone) is well de- veloped. The tootli figured by Hall as M-' (op. cit., fig. 6) is 50 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY actually a specimen of M^ in which both unions of the metacone are present, and the mesoloph is very long. The range of variation in tooth size is indicated in Table 4. The mental foramen lies beneath the diastema, as in C. dentalis, and the size and shape of the masseteric fossa is also like that of C. dentalis. CoPEMYS KELLOGGAE (Hoffmeister) Peromyscus Tcelloggae Hoffmeister, 1959, p. 698. This species, from the late Miocene Niobrara River fauna of Nebraska is referable to Copemys. The anteroloph is a single cusp, close to the metaeonid (Hoffmeister, 1959, fig. 1 B). There is a long mesolophid, reaching nearly to the lingual margin of the crown. The hypoconulid is very well developed. The upper molar described by Hoffmeister as Miochomys niohrariensis does not appear to be referable to the same form as do the lower teeth, although they are of the appropriate size to belong together. The metacone has not shifted its union away from the hypocone, and the posterior cingulum is short. The separation of the tooth into three transverse lobes is not char- acteristic of Copemys. Copemys esmeraldensis n. sp. Figure 9 Type: M.C.Z. No. 7644, right jaw with Mi and M3 and incisor. Hypodigm: Type; M.C.Z. No. 7645, right jaw fragment with Mi; M.C.Z. No. 7646, edentulous right jaw; and M.C.Z. No. 7647, left maxillary fragment with M^. Diagnosis: Jaw heavier than in C. dentalis. with chin process; masseteric fossa not reaching as far ventrad on angle as in C. dentalis and upper border of masseteric fossa more pronounced, but mucli less so than in C. loxodon; mental foramen beneath Mi rather than in front of it ; fossa between M3 and coronoid as in C. dentalis; anteroconid area highly complex ; mesolophid present and long, though sometimes low ; sometimes an accessory crest running buccad from the entoconid to the buccal margin of the tooth; hypoconulid of Mi distinct; metacone of M^ uniting with posterior cingulum rather than with hypocone ; lower incisor wide; larger than C. dentalis; tooth measurements as given in Table 4. 51 •2 ti d ^1 y. a'- -- t~ CO 00 ^IM H 55 So i5 0-5> O CR rH •2 rii a o Is o 5 £? o _« ^- ^ & & ii S ^ IS S - 3 '^ :3 5^ 5: rt ^ ^ 52 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY Distrihution : Lower Pliocene Fish Lake Valley beds, Esmer- alda Formation of Nevada. All material came from locality A shown by Hall (1930c, pi. 37, fig. 1). Description: As shown by the two specimens of Mi preserved in the present collection (Fig. 9 B, C) there is considerable variability in pattern in this tooth. From what is known of the variability in the Oligocene Eumys, and from the detailed studies of Peromyscus by Hooper (1957), however, it seems obvious that a great deal of individual variation can be expected within a single species of cricetid. Initially, because the specimens come from a single locality, all the Fish Lake Valley ericetids were referred to a single species. As the study proceeded, however, it became apparent that not only is the material in the present collection all much larger than Hall's material, but there is also the much greater complexity of the anteroconid region and the rather striking difference in the jaw structure, including the masseteric fossa and the position of the mental foramen. These differences make it seem unlikely that this material is conspecific with C. clentalis, even though the present collection came from the same spot as the University of California material. The pattern of M^ (Fig. 9 A) is fundamentally intermediate between that of Euynys clegans (AVood, 1937, fig. 57) and that of such living species of Peromyscus as P. nuclipes (Hooper, 1957, fig. 19). The anterocone is a large cusp, continued both buccally and lingually by narrow ridges. Buccally, there are two such ridges, separated by a groove, as in P. nudipcs. The anterior arm of the protocone unites with the middle of the anterocone. The posterior arm of the protocone unites with the paracone to form a protoloph as in Eumys. In general, in Peromyscus, the paracone is behind the protocone, though this is not always the situation. This shift is just beginning in the present form. The mure is longer than in Peromyscus. The mesoloph, as in Eumys, is a continuation of the anterior arm of the hypocone, instead of appearing more closely related to the paracone, as in Peromyscus (Hooper, 1957, figs. 9, 15, 16 and 19). The mesoloph is directed into the base of the metacone, rather than extending freely to or toward the buccal margin of the tooth as in Paciculus (Black, 1961c, fig. 4) or some species of Pero7nyscus (Hooper, 1957, figs. 18-19). The most progressive character of this tooth is the union of the metacone with the posteroloph, rather than with the hypocone. In this it resembles C. dentalis and is more advanced than 3Iiochomys niobraricnsis. CLARK, DAWSON, WOOD: FOSSIL MAMMALS OP NEVADA 53 Even thounfh this union is characteristic of Peromyscus, not all members of that genus are as advanced as is Copemys dcntaUs. The measurements of this specimen are : anteroposterior, 2.27 mm; width protoloph, 1.48; width metaloph, 1.52. The two sioeeimens of M^ are ratlier different, as well as being in very distinct stages of wear. Tlie unworn tootli (Fig. 9 C) shows tliat the anterolophid is a very eomph\\ area, being formed of an anteroeoiiid (partly divided in two), a large lingual eu.sp, a buccal marginal crest from the anteroconid, and a long, narrow crest from the lingual cusp almost to the buccal margin. The worn sjiecimen (M.C.Z. No. 7644, Fig. i) B) cannot be shown to have had a different pattern. This area is much more complex than anything seen in any other species of Copemys, or in Eumys, though the beginnings of subdivision of the anteroconid may be seen in E. ohliquidens (Wood, 1937, fig. 62) and E. spo'kancnsis (White, 1954, fig. 47). This area is much more complicated than is the corresponding area of any of the Peromyscus teeth figured by Hooper, though it is approached in P. nndipes (Hooper, 1957, fig. 19). The protoconid and metaconid unite at the anterior end of the metaconid, the latter cusp being the more anterior. This condition is typical of both Copemys and Peromyscus, and is a contrast to Eumys, where the primary union is at the posterior side of the protoconid. In C. loxodon, the metaconid is more isolated than in C. esmeraldensis. The ectolophid (in the sense of Wood and Wilson, 1936; this ridge is called the mure by Hooper, 1957, fig. 1) is much longer than in Eumys, being like that of Peromyscus in this respect. What may be a mesolophid extends from the middle of the ectolophid almost to the lingual margin of the crown, not being as elevated as is the ectolophid (Fig. 9 C). In M.C.Z. No. 7644 (Fig. 9 B), the mesolophid looks as if it were perhaps more correctly identified as the posterior arm of the protoconid, as in some specimens of Eumys (AVood, 1937, fig. 58). There is a connection in this same specimen between this lingual crest and the anterior side of the entoconid (Fig. 9 B). The entoconid connects with the ectolophid in front of the hypoconid, rather than with the anterior arm of the hypoconid as in Oligocene species of Eumys, resembling Eumys eUensis (Black, 1961c, fig. 3 A) and Pero- myscus in this respect. There is much more of a hypoconulid than in Eumys. An unusual crest that extends buccally from the point where the entoconid meets the ectolophid in one specimen (Fig. 9 C), is completely absent in the other (Fig. 9 B). This 54 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY crest is present in many of the species of Peromyscus discussed by Hooper, the closest similarity being seen in P. nuttalli (Hooper, 1957, fig. 18). This crest, which seems to be fairly important in Peromyscus, has been called the ectolophid by Hooper. It is completely unrelated to the ectolophid as that term was used by Wood and Wilson (1936) and does not seem to have been discussed by anyone else. This crest is clearly a neomorph in Copemys and Peromyscus, and does not arise as a buccal ex- tension of the mesoconid, which Wood and Wilson would have considered to be a buccal part of the mesolophid. Both of these teeth belong to Hooper's pattern type g (1957, p. 11). Of the species he studied, pattern g occurs in less than ten per cent of all except P. maniculatus (20%), P. truei (20%), P. hylocetes (25%), P. oaxacensis (60%) and P. mcxicanus (50%). A well developed buccal crest (Hooper's ectolophid) is present in all P. hylocetes and P. oaxacensis ; 90 per cent of P. yucatane7isis ; 80 per cent of P. nasutus and P. difficilis; 70 per cent of P. hoylei; 30 per cent of P. leucopus and P. mexicayius ; 20 per cent of P. melanotis and less than ten per cent of the remainder. Fig. 9. Copemys esmeraldensis n. sp. Teeth X 10, jaw X 5. A, LM^, M.C.Z. No. 7647; B, type, EMi and M3, spaced as in the specimen, M.C.Z. No. 7644; C, EMi, M.C.Z. No. 7645; D, cross section of RIi, M.C.Z. No. 7644, type; E, cross section of RIi, M.C.Z. No. 7646; F, lateral view of lower jaw, M.C.Z. No. 7644, type. Outline portion restored from M.C.Z. No. 7646. The incisor slid back into the alveolus before fossilization. CLARK, DAWSON, WOOD: FOSSIL MAMMALS OP NEVADA o5 Therefore, as far as the avaihihh' data go, C. esmeraldensis seems closest to P. oaxacensis, aiiioii«;- the species studied by Hooper, ill these respects. The single specimen of M3 (M.C.Z. No. 7644, Fig. 9 B) is both badly worn and broken. Hooper does not discuss this tooth in Peromyscus. This tooth is very different from that of Enmys. There is no anterior cingulum, and the metacoiiid is continuous along the anterior edge of the tooth to the protoconid. From here, a broad ridge runs to the lingual margin of the tooth, showing slight irregularities at the tooth margin, which suggests that it may include a mesolopiiid and an entoconid, the latter being well forward of the hypoconid. A broad postcrolophid extends across the rear of the tooth. The incisor is broad, with a rounded anterior face, and is proportionately wider and rounder, laterally, than in C. dentalis. The enamel is fairly thick, and extends well onto the lateral side of the tooth (Fig. 9 D-E). The pulp cavity enlarges toward the enamel-covered side of the tooth (Fig. 9 E). The base of the incisor is in the ascending ramus behind and at or above the level of M3 (Fig. 9 F). Three lower jaws are preserved permitting the composite restor- ation shown in Figure 9 F. There is a prominent chin process in M.C.Z. No. 7646, not preserved on the other specimens. Such a process does not seem to have been present in C. dentalis (Hall, 1930c, fig. 16). This difference may be sexual, but the overall differences in size and in tooth pattern suggest that it is not. The symphysis is weakly ridged, indicating that there may have been a strong Transver.sus mandibulae muscle and free movement between the mandibles. The alveolar border drops abruptly in front of Ml, as in C. loxodo7i, in contrast to its more gentle slope in C. dentalis and C. longidens. The prominent mental foramen lies beneath the anterior root of Mi, as in C. loxodon, instead of beneath the diastema as in the other species, and opens anterad rather than slightly upward. The masseteric fossa is broad and flat. The masseteric knob is clearly differentiated, beneath the posterior end of Mi, farther to the rear than in C. dentalis (Hall, 1930c, figs. 16-17). The masseteric fossa does not extend as far ventrally in the angle as in C. dentalis. The coronoid process passes the alveolar border by the middle of Mo. There is a prom- inent fossa between M.-j and the base of the coronoid, which con- tains one or more nutritive foramina, as in othei- species of the genus. 56 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY At the present time, little can be said of the interrelationships of the five species of Copcmys. C. esmeraldensis is probably the closest to Peromyscus. C. loxodon is apparently the most aber- rant. C. longidens may be ancestral to C. esmeraldensis. The differences between C. longidens and C. dentalis are not great except in size, which may not be very significant, phylogenetic- ally. Copemys kelloggae is fairly close to C. longidens and C. dentalis. These three species are all closer to each other than any is to C. esmeraldensis or C. loxodon. Family CASTORIDAE EucASTOR DiviDERUs Stirton, 1935 Figure 10 Aside from lagomorph material, fragmentary remains of this beaver are the most abundant fossils in the collection. The pres- ent material adds some features to the full account of this species given by Stirton (1935, pp. 431-437). Two upper premolars, M.C.Z. Nos. 7648 and 7649, show interesting pattern variants, and M.C.Z. No. 7650 is an upper deciduous premolar, hitherto not described. In both of the permanent premolars, the anteroloph is very long, covering the entire front of the tooth, as opposed to the earliest stage of wear figured by Stirton (1935, fig. 107). The parastria is present in one specimen (Fig. 10 A), but is con- verted to a parafossette in the other (Fig. 10 B). In each speci- men, there is a small enamel lake, of very uncertain homology, in the middle of the paracone. The mesoflexus in the less worn specimen extends across the tooth to the posterior margin of the crown, where it forms a distinct flexus behind the hypocone (Fig. 10 A). In the more worn specimen, this is cut off from the posterior margin of the crown, as in Stirton 's specimens. There is considerable variation in the region of the metaflexus. In Stirton 's least worn tooth (1935, fig. 107), the metaflexus opens to the rear, and there is a small isolated lake behind it. In M.C.Z. No. 7648, the metaflexus is a triangular valley, opening posteriorly (Fig. 10 A). In the more worn premolar, the meta- fossette is widely separated from the rear of the tootli, resembling Stirton 's second stage of wear {op. cit., fig. 107), but retaining a minute lake behind the fossette. Presumably these variants indicate that there are numerous minor irregularities at the surface of the unworn crown, and CLARK, DAWSON, WOOD: FOSSIL MAMMALS OP NEVADA 57 that tliese ai-e liio-lily variable, ^iviii^' a variety of slightly dif- ferent patterns with wear. The exact angle at which the wear surface cuts the crown may also make appreciable pattern dif- ferences. The upper milk tooth (Fig. 10 C) is clearly deciduous, as it is much lower crowned than are the permanent teeth. There was a large single root under the anterior part of the crown, and two smaller ones under the posterior part. The anterior root, however, is proportionately smaller than in P^. The hypostria and mesostria extend almost to the base of the crown. The metastria is long, but not (juite as long as the other two. The mesoflexus and metaflexus interconnect, isolating a circular buc- cal mesostyle. The metaflexus runs transversely across the pos- terior part of the tooth, and is much more extensive than in P-*. The paraflexus is already transformed into a parafossette. Fig. 10. Eitcastor dividcrus, X 5. A, EP^, M.C.Z. Xo. 7648; B, RP-», :\r.C.Z. Xo. 7G49; C, EdP^, M.C.Z. Xo. 7650. Family IIETEROMYIDAE DiPRioNOMYS cf. PARVUS Kellogg, IJilO Two isolated and unassociated unworn cheek teeth are perhaps referable to this species: M.C.Z. No. 8535, RP^ and M.C.Z. No. 8536, RM2. Since the previously known material is badly worn, they add considerably to our knowledge of this rodent. The premolar (Fig. 11 A) is clearly that of a heteromyine, in view of the two-cusped protoloph. The buccal cusp is quite small, and distinctly subsidiary to the main cusp. The metaloph forms a crest of nearly uniform height, running fi-oni the meta- eone to the hypostyle, and passing behind the slightly higher hypocone. The hypostyle is at about a right angle with the rest of the metaloph. The valley between the hypostyle and the hypocone curves buccad behind the latter, but would not persist verv long with wear. 58 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY The molar (Fig. 11 B) is eonsiderd to be M2 rather than M^ because of its anteroposterior diameter, which is less than would be expected in Mj (cf. Wood, 1935a, Table II). Both lophs are strong, and the cusps form only minor enlargements. The pro- toconid is the only really distinct cusp. There is a prominent valley between the protoconid and protostylid, which would re- sult in the formation of a Y-pattern, a characteristic heteromyine feature (Wood, 1935a, p. 165). The hypolophid is almost a straight crest, the cusps being very indistinct. The least depth of the central valley is between the two stylids, and the valley would thus become closed, buccally, after a moderate amount of wear. Slight further wear would unite the lophs just linguad of the bases of the protoconid and the hypoconid, isolating the buccal part of the valley as a lake. This double union is char- acteristic of Diprionoynys (Wood, 1936b, p. 118). Fig. 11. Diprionomys cf. parvus, X 10. A, EP-^, M.C.Z. No. 8535; B, RM2. M.C.Z. Xo. 8536. These specimens are the first from the Fish Lake Valley beds that can be referred to Diprionomys, Hall's two species (D. tertius and D. quartus) being perognathines which AVood (1935a, pp. 92-96) placed in a separate genus, Pcrognathoides. The two teeth here described are, however, clearly heteromyines, and seem clearly to be referable to Diprionomys. They are the right size to belong onh' to D. parvus among descril)ed species, and cannot at the present time be separated from that species, even though the type is appreciably later (Thousand Creek). The measurements of these specimens are as follows : M.C.Z. No. 8535, Rp-i M.C.Z. No. 8536, RMo A small collection of Pliocene mammals, from the type locality of the Fish Lake Valley local fauna of Nevada, adds ap])i'ecial)l.v to our knowledge of that fauna. Included ai'e : a talpid, Doiiniin- oides; Hesperolagomys, a new genus of ochotonid ; a new species, C. esmeraldcnsis, of the cricetid Copcmys; and the heteromyid antfi-d- l)osterii)i' width anterior orest wiilth, ixistcrior crest 1.40 0.77 1.43 1.02 1.27 1.23 SUMMARY CLARK, DAWSON, WOOD: FOSSIL MAMMALS OF NEVADA 59 Diprionomys. The most abundant material, referable to the rabbit JhjpoJaijus f()nti)i(ilis, and the l)eaver Eucasfor dividerus, adds to our kno\vU'd<«(' of the dentition of these forms. These materials permit a discussion of the interrelationships and evolutionary trends amon^ Tertiary North American ocho- tonids and cricetids. Hespcrolagornys is an unusually primitive Pliocene ochotonid, ajiparently representing: the survival of a line derived from the primitive stock of the family, ])erha})s from Desmatolagiis. The cricetid genus Copemys is revised, and three species previously included in Pcro)nyscus are referred to it. Al- though cricetids are abundant in the middle Oligocene, the North American Miocene and Pliocene cricetids are largely limited to intermontane areas, with only two isolated teeth from the late Miocene Niobrara River local fauna of Nebraska and rare speci- mens from the Thomas Farm local fauna of Florida. They do not appear in numbers in the plains until the late Pliocene. Competition with entoptychine geomyids and with heteromyids may be the factors involved in the reduced numbers of cricetids in the Miocene and early Pliocene. EEFEEENCES Black, C. C. 1961a. Fossil mammals from Montana. Pt. I. Additions to the T.ate Miocene Flint Creek Local Fauna. Ann. Carnegie Miis., 36: 69-76. 1961b. New rodents from the early Miocene deposits of Sixty-Six Mountain, Wyoming. Breviora, Mus. Comp. Zool., No. 146: 1-7. 1961c. Kodents and lagomorphs from the Miocene Fort Logan and Deep Eiver formations of Montana. Postilla, Yale Peabody Mus., No. 48: 1-20. BOHLIN, B. 1942. The fossil mammals from the Tertiary do])osit of Taben-buluk. Western Kansu. Pt. I. Inseetivora and Lagomorpha. Palaeont. Sinica, n.s. C, 8 a: 1-113. Burke, J. J. 1941. New fossil Leporidae from Mongolia. Amer. Mus. Novitates, No. 1117: 1-23. Cope, E. D. 1874. Notes on the Santa Fe marls and some of the contained verte- brate fossils. Proc. Acad. Nat. Sci. Phila., 26: 147-152. 1875. Keport on the geology of that part of northwestern New Mexico examined during the field season of 1874, by E. D. Cope, palae- ontologist and geologist. Appendix LL, Ann. Eept. Chief of Engrs., Ann. Eept. Geogr. Ex]il. & Surv. West of 100th Merid- ian, Washington: 981-1036. 60 BULLETIN: MUSEUM OP COMPARATIVE ZOOLOGY Dawson, M. E. 1958. Later Tertiary Leporidae of North America. Univ. Kansas Paleont. Contrib., Vertebrata, 6: 1-75. Forsyth Major, C. I. 1899. On fossil and Recent Lasomorpha. Trans. Linn. Soc. London, (2), Zoology, 7: 433-520. Galbreath, E. C. 1953. A contribution to the Tertiary geology and paleontology of northeastern Colorado. Univ. Kansas, Paleont. Contrib., Ver- tebrata, 4: 1-120. Green, M. 1956. The lower Pliocene Ogallala-Wolf Creek vertebrate fauna, South Dakota. Jour. Paleont., 30: 146-169. Hall, E. R. 1930a. A new genus of bat from the later Tertiary of Nevada. Univ. Calif. Publ., Bull. Dept. Geol. Sci., 19: 319-320. 1930b. Rodents and lagomorphs from the Barstow beds of southern California. Univ. Calif. Publ., Bull. Dept. Geol. Sci., 19: 313-318. 1930e. Rodents and lagomorphs from the later Tertiary of Pish Lake Valley, Nevada. Univ. Calif. Publ., Bull. Dept. Geol. Sci., 19: 295-312. Hay, O. p. 1902. Bibliography and catalogue of the fossil A'^ertebrata of North America. Bull. U.S. Geol. Surv., 179: 1-868. HOFPM BISTER, D. F. 1959. New cricetid rodents from the Niobrara River fauna, Nebraska. Jour. Paleont., 33: 696-699. Hooper, E. T. 1957. Dental patterns in mice of the genus Peromyscus. Misc. Publ. Mus. Zool., U. Mich., 99: 1-59. MacInnes, D. G. 1953. The Miocene and Pleistocene Lagomorpha of East Africa. Brit- ish Mus. (Nat. Hist.), Fossil Mamm. Africa, 6: 1-30. McKbnna, M. C. 1960. The Geolabidinae. A new subfamily of early Cenozoic erinace- oid insectivores. Univ. Calif. Pu1)l. Geol. Sci., 37: 131-164. Matthew, W. D. 1909. The Carnivora and Insectivora of the Bridger Basin, middle Eocene. Mem. Amer. Mus. Nat. Hist., 9: 291-567. Patterson, B. and P. O. McGrew 1937. A soricid and two erinaceids from the AVhite River Oligocene. Geol. Ser. Field Mus. Nat. Hist., 6: 245-272. Reed, K. M. 1960. Insectivores of the middle Miocene Split Rock local fauna, Wy- oming. Breviora, Mus. Comp. Zool., No. 116: 1-11. Stirton, R. a. 1935. A review of the Tertiary beavers. Univ. Calif. Pul)l., Bull. Dept. Geol. Sci., 23: 391-458. CLARK, DAWSON, WOOD : FOSSIL MAMMALS OF NEVADA 61 White, T. E. 195-1. Preliminary analysis of the fossil vertebrates of the Canyon Ferry reservoir site. Proc. U.S. Nat. Mus., 103 (3326) : 395-438. Wood, A. E. 1935a. Evolution and relationships of the heteioinyid lodcnts with new forms from the Tertiary of western North America. Ann. Car- negie Mus., 24: 73-262. 1935b. Two new genera of cricctid rodents from the Miocene of west- ern United States. Anier. Mus. Novitates, No. 789: 1-3. 1936a. The crieetid rodents described by Leidy and Cope from the Tertiary of North America. Amer. Mus. No%'itates, No. 822: 1-8. 19361). Fossil heteromyid rodents in the collections of the University of California. Amer. Jour. Sci., (5) 32: 112-119. 1936c. Geomyid rodents from the middle Tertiary. Amer. Mus. Novi- tates, No. 886: 1-31. 1937. The mammalian fauna of the White Eiver Oligoeene. Pt. II. Rodentia. Trans. Amer. Phil. Soc, n.s. 28: 155-269. 1947. Miocene rodents from Florida. Bull. Mus. Comp. Zool., 99: 489-494. Wood, A. E. and R. W^ Wilson 1936. A suggested nomenclature for the cusps of the cheek teeth of rodents. Jour. Paleont., 10: 388-391. (Received December 1962) ADDENDUM Since this manuseiMpt was completed, three papers, two deal- ing with Barstovian and Clarendonian, and one with Arikareean, cricetids have appeared. Shotwell (1963, p. 49) refers a lower jaw from the Clarendonian of eastern Oregon to Peromy.^ctis cf. dentalis. James (1963, pp. 112-129) describes a considerable collection from the Clarendonian of the Cuyama area of Cali- fornia as Peromysciis russelli, and refers a single lower jaw from the Barstovian of the same area to Peromysciis aff. dentalis. Macdonald (1963, pp. 198-201) describes Eumys hlocli and E. wood}, and lists Scottimus, sp. indet., from the Arikareean of South Dakota. Shotwell 's specimen is a jaw containing the first lower molar of an animal very similar to the type of Copemys dentalis (Fig. 8A). His figure (1963, fig. 52a) suggests an almost complete union of the anterolophid with the protoconid, which is incor- rect, as there is a broad but shallow valley in this area, similar to that shown in Figure 8A. The metaconid is close to the anteroconid, also as in C. dentalis, to which this specimen clearly should be referred. 62 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY James' description of Pcromyscus russelli indicates that it is very close to its contemporary, Copemys csmcraldensis, and that the two are certainly cono'eneric. The Cnyama form shows a union of the paracone of M^ with both the anterior and posterior arms of the protocone, a condition more progressive than that seen in C. esmeraldensis. This type of union is present on M^^ as well (James, 1963, figs. 47, 52), and this species has thus progressed half way from the Eumys condition toward the situation in Peromyscus, where the union is exclusively through the anterior arm of the protocone. As in Copemys, the metacone of Ml has shifted its point of attachment from the hypocone to the posteroloph, whereas this shift has not occurred in 'M-'^. In the lower teeth, the pattern of M3 is almost identical in the two populations (compare Fig. 9B and James, 1963, fig. 53a). In M] , the California specimens show the same variation as to the presence or absence of the crest called the ectolophid by Hooper and by plames (but not that called the ectolophid by Wood and Wilson). The peculiar accessory crests and cusps of the anteroconid region of C. esmeraldensis (Fig. 9C) do not seem to be present in the California species. In spite of the similarity in pattern, there are significant distinctions in size, especially of the first molars. The length and width measurements of M^ of M.C.Z. No. 7647 exceed those of the mean of P. russelli (James, 1963, Table 22) by about six times the standard deviation, and the length of the smaller M^ of C. esmeraldensis exceeds that of P. russelli by over five times the standard deviation. The transverse diameter of M^ of the larger Nevada specimen is larger by nearly 3.5 S.D. The third molar of M.C.Z. No. 7644 is larger than that of any specimen of P. russelli, but the difference is not significant. The probability that either measurement of M^ or of Mj of C. esmeraldensis falls wdthin the limits of variation for the population of P. russelli is thus considerably less than .001, and is therefore negligible. These factors all indicate that Peromyscus russelli should be referred to Copemys, and that C. russelli and C. esmeraldensis are closely related but distinct species. The specimen referred by James to Peromyscus aff. dentalis is appreciably smaller than are the other specimens of C. den- talis, as James indicates (1963, p. 129), with an alveolar length of only 3.6 mm (cf. Table 4, where that of C. dentalis is given as 4.35-4.40 mm). It seems probable that this difference is great CLARK, DAWSON, WOOD: FOSSIL MAMMALS OF XEVADA 63 enough to place James' specimen outside the limits of C. dentalis. It is presumably also referable to Copemys. PcroDiyscus parvus Sinclair (1905, p. 126) from the middle John Day of Oregon, was included by James as a rather dis- tinctive species of Peromyscus, only (luestionably ret'eraljle to the modern genus (1963, p. 128). Study of the only known specimen shows that it is clearly a small species of Lcidymys. In liis paper on Arikareean fossils from South Dakota, Mac- donald describes Eumys black i (1963, p. 198, fig. 21), which is clearly congeneric with Coiimus, and E. woodi {op. cit., p. 199, fig. 22), which is close to E. eliensis. He also refers two isolated upper molars to Scott inins sp. indet., thus extending the range of this genus into the Arikareean. ADDITIONAL KEFERENCES James, G. T. 1963. Paleontology and nonniarine stratigraphy of the Cuyania Bad- lands, California. Part 1. Geology, faunal interpretations and systematic descriptions of Chiroptera, Insectivora and Eodentia. Univ. Calif. Publ. Geol. Sei., 45: 1-154. Macdonald, J. R. 19G.3. The Miocene faunas from the Wounded Knee area of western South Dakota. Bull. Amer. Mus. Nat. Hist., 125: 1.39-238. Shotwell, J. A. 1963. The Juntura Basin: studies in earth history and paleoecology. Trans. Amer. Phil. Soc, n.s. 53: 1-77. Sinclair, W. J. 1905. New or imperfectly known rodents and unyuhites from the Jolui Day series. Univ. Calif. Publ., Bull. Dept. Geol., 4: 125-143. Bulletin of the Museum of Comparative Zoology H A H \ A j{ I) 11 N I \ !•; i{ s I r ^ Vol. 131, No. A AMERICAN SPIDERS OF TlIK GENUS PIIORONCIDJA (ARANEAE: TIIERIDIIDAE) By Herbert W. Levi CAMBEIDGE, MASS., U.S.A. PRINTED FOR THE MUSEUM April 30, 1964 Publications Issued by or in Connection WITH THE MUSEUM OF COMPARATIVE ZOOLOGY PIAEVAPvI) UNIVERSITY Bulletin (octavo) 1863 — The current volume is Vol. 131 . Breviora (octavo) 1952 — No. 203 is current. Memoirs (quarto) 18G4-1938 — Publication terminated with Vol. 55. Johnsonia (quarto) 1941 — A publication of the Department of Mollusks. Vol. 4, no. 41 is current. Occasional Papers of the Department of Mollusks (octavo) 1945 — Vol. 2, no. 28 is current. Proceedings of the New England Zoological Club (octavo) 1899-1948 — Published in connection with the Museum. Publication terminated with Vol. 24. The continuing publications are issued at irregular intervals in num- bers which may be purchased separately. Prices and lists may be obtained from the Publications Office of the Museum of Comparative Zoology, Cambridge 38, Massachusetts. Peters' Check-List of Birds of the AVorld. Volumes 1, 4 and (> are out of print ; volumes 2, 3, 5, 7, 9, 10 and 15 are currently available. Phylogeny and Evolution of Crustacea. Proceedings of a confer- ence held at Cambridge, Mass., March 6-8, 1962. H. B. Whittington and W. D. I. Rolfe, editors. Cambridge, Mass., 192 pp., 80 figs., 1963. Cloth bound. $6.75. Fishes of the Gulf of Maine, by Henry B. Bigelow and William C. Schroeder. Washington, viii - 577 i)p., 1953. Photo-offset reprint. $6.50. Publications of the Boston Society of Natural History The remaining stock of the scientific periodicals of the Boston Society of Natural History has been transferred to the Museum of Comparative Zoology for distribution. Prices for individual numbers may be had upon request. Bulletin of the Museum of Comparative Zoology H A 1{ V A J{ I) [• N I V K K S I T Y Vol. 131, No. 3 ami^:hican spideks of the genus piioroncidia (araneae: tiieriditdae) By Herbert \V. Levi CAMBRIDGE, MASS., U.S.A. PRINTED FOR THE MUSEUM April, 1964 Bull. .Mus. Coiiip. Zool., Harvard Univ., 131 (3): 65-86, April, 1964 No. 3 — American Spiders of the Genus Phoroncielia {Araneae: Theridiidae) By Herbert \V. Levi Phoroncielia are mostly small spiders with the abdomen hard and sclerotized but of various shapes. The diversity in shape has caused araelmologists to assign different species to separate genera. Thus the synonymy of generic names (Levi and Levi, 1962) is long. Some species are similar to those placed in Dipoena (Hickman, 1951). However Dipoena females always have four seminal receptacles, while Fhoroncidia have two. In Dipoena, males, if the palpal embolus is long it curls counter- clockwise in the left palpus; in Phoroncidia, the direction is the reverse. It is believed that the similarities, heavy sclerotization of the abdomen (only some species of Dipoena), projecting eye region of the carapace, and the relatively long fourth leg, have independently evolved. Xothing is known of the natural history of Phnroyicidia species. The Central and South American P. fricuspidata, group, leav- ing three spines on the abdomen (Figs. 50, 56), is closest to its African relatives, some of which have five spines on the abdo- men : two anteriorly, as in the American species, and three pos- teriorly. The commonest species is the North American P. ameri- cana, closely allied in shape and appearance to the European P. paradoxa (Lucas), and the Japanese P. pilida (Karsch) ; most other species are very rare. Almost half the specimens available were collected during the nineteenth century and these old specimens, collected by entomologists, are often in poor condition, having been speared on insect pins. The scarcity of specimens, and the abundance of species, make it difficult to match sexes. The paper thus reports only our very incomplete knowledge of the American species. Despite this, I have resisted the temptation of quoting unsupported literature records. T have not been able to examine the Mello-Leitao collection to verify his many records of P. tricuspidata. I suspect many are misidentified. This paper, along with my others on American theridiid spiders, would not have been possible without the help of nu- merous colleagues who made rare specimens available. I extend sincerest thanks to Prof. j\I. Vachon of the Museum National d' Histoire Xaturelle, Paris (MNHN), Dr. A. Collart and Mr. J. 68 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY Kekeiibosch of the Institut Royal des Sciences Naturelles de Belgique (ISNB), Dr. L. Brundin of the Natural History Mu- seum Stockholm (RMS), Prof. G. C. Varley and Mr. E. Taylor of the Hope Department of Entomology, Oxford University, Dr. G. Owen Evans, Mr. K. Hyatt and IMr. D. Clark of the British Museum (Natural History) (BMNH) ; Dr. W. J. Gertsch of the American Museum of Natural History (AMNH), Dr. 0. Kraus of the Senckenberg Museum (SMF), and Mr. W. Starega of the Polish Academy of Sciences, Warsaw. Dr. P. E. Vanzolini and his colleagues of the Departamento de Zoologia, Sao Paulo, pro- vided locality information. Fr. Chrysanthus checked the latin- ization of specific names. The examination of types in European museums was made possible by a National Science Foundation Grant (G-4317), and the completion of the revision by a grant from the National Institutes of Health (AI-01944). Phoroncidia Westwood Phoroncidia Westwood, 183.5, Zool. Jour., 5: 452. Type species lay mono- typy: P. aculeata Westwood, 1835, ibid., 5: 453, tab. 22, fig. 9, 9,$ from ^lalaya. Note. It is not known whether Westwood 's specimens still exist. Only a few specimens determined by Berland in the Paris museum were examined. We recently published the synonymies (Levi and Levi, 1962). Diagnosis. Theridiid spiders with colulus replaced by two setae, usually hidden underneath a sclerotized ring surrounding spinnerets. Carapace with eye region projecting above clypeus. Small chelicerae. Legs very short; fourth leg usually longer than first. Abdomen of various shapes, heavily sclerotized, often leathery, folded or with strong spines, humps, tubercles or ex- tensions. Epigynum a heavily sclerotized plate with openings, often indistinct, in the center or on the posterior border. Juvenile specimens may also have the epigastric area sclerotized. Only examination for the presence of seminal receptacles will deter- mine whether the specimen is mature. The palpus usually has a paracymbial hook on or near the edge of the cymbium and the median apophysis probably does not touch the hook. Distribution. Species are found in all parts of the world ex- cept northern Europe and western North America. Misplaced species. Herihertvs fJavomacxlatns Keyserling, 1891, Die Spinnen Amerikas, Theridiidae, 2(1) : 223. Ulesatiis LEVI: .\Mi:iil(AX I'lIOIJOXflDIA 6!) flavoiiuiciilata, — Petninkcvilcli. 1!)11, Uull. Aiiht. Mus. X;i1. Plist., 2!*: 214 ~ DipoiiKt flartjiiKicuhftd ( K('ys('rliii-. 36 = Arancus alhopinictahis (Tae- zajiowski), AK(UOrrDAE. KKY TO A.MKinCAX I'llOl.'OM 1 1 )I A 1.1. AliiloiiH'u with spines, liunips, tubercles or pro.iectioiis 5 11). Ahdoiuoii witliout spines, liumps, tubercles or projections 2 2a. Dorsum of abdomen witli many trapezoidal plates (Fig. 11); Amazon studo 2b. Dorsum of abdomen covered by one single plate 3 3a. Trapezoidal imiiressions on dorsal jjlate (Fig. 17) ; Tjower Amazon lo)itiicrp.s 31). Dorsal plate without trapezoidal impressions 4 4a. Lateral eyes on tuljercles (Fig. 2) ; Peru nioiialxnuha 4b. Lateral eyes not on tubercles (Fig. 23) ; Est. Rio de Janeiro riibroinaciihitd 5a. Abdomen subcii-cular in outline in dorsal view (Fig. 20) 6 5b. Abdomen tra])('zoidal, subtriangular or squarish with posterior i)ro- jections 7 6a. Abdomen with only a median dorsal hump (Fig. 20); Chile snituJa 6b. Abdomen with a median dorsal hump and paired humjis posteriorly (Levi, 1955, figs. 7, 8) ; eastern Canada, eastern L^nited States, Cuba, Jamaica americana 7a. Abdomen widest anteriorly and with a median dorsal posterior s])ine (Figs. 29, 45, 56) 11 7b. Abdomen as wide anteriorly as posteriorly, or wider ])osteriorly than anteriorly, usually without median posterior spine 8 8a. Abdomen trapezoidal in dorsal view with five dorsal spines (Figs. 36, 37) ; Minas Gerais Una 8b. Abdomen otherwise 9 9a. Abdomen with sides tuberculate and wrinkled (Figs. 32, 34) ; Chile margamarga 9b. Abdomen with at most median dorsal tubercles; with sclerotized plates 10 10a. Abdomen with longitudinal row of dorsal tubercles (Figs. 40, 41) ; Chile coquimbo 10b. Abdomen with sclerotized spots but without tubercles (Figs. 25, 26) ; Chile nicoleti 11a. Median posterior dorsal spine longer than anterior spines (Fig. 45) 12 lib. Three spines subequal in length 13 70 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 12a. Innumerable dorsal circular plates of abdomen almost touching (Fig. 29) ; Venezuela ravot 12b. Fourteen dorsal circular plates, far apart (Fig. 45) ; Peru sciifellata 13a. Epigynum with a distinct me(liaii opening (Fig. 78) ; Est. Sao Paulo to Est. Eio Grande do 8ul rcimoseri 131). Epigynum otherwise 14 14a. Epigynum with a V-shaped depression anterior to and between two dark spots containing openings (Fig. 73); Colomliia sahoya 14b. Epigynum otherwise 15 15a. Epigynum with paired openings near posterior margin (Fig. 58) ; Peru flavolim'bata 15b. Epigynum otherwise 16 16a. Openings of epigynum indistinct lateral slits (Fig. 47) ; Est. Guana- bara, Rio de Janeiro tricnspidata 16b. Epigynum otherwise 17 17a. Epigynum with a pair of distinct openings in a flat plate, anterior to a transverse keel (Fig. 63) ; southern Mexico, Central America triunfo 17b. Epigynum otherwise 18 ISa. Epigynum with a median depression containing openings 19 18b. Epigynum without median depression, openings a pair of slits (Fig. 68) ; Minas Gerais hiocellata 19a. Spines relatively short (Fig. 56) ; distinct pair of openings in de- pression of epigynum (Fig. 53) ; Paraguay cribrata 19b. Spines relatively long (Fig. 86) ; openings in epigynum depression indistinct (Fig. 83) ; Venezuela gira Phoroncidia moyobamba sp. n. Figures 1-5 Wihrada longiceps, — Archer, 1950, Paper Alabama Mus. Nat. Hist., no. 30: 27, pi. 4, fig. 4, $. Not IVibrada longioeps Keyserling. Type. Male holotype from Moyobamba, San Martin, Peru, 20 Dec. 1946 (J. C. Pallister), in the American Museum of Natural History. The name is a noun in apposition after the type locality. Description. Carapace, sternum dark brown ; legs lighter brown. Abdomen, dorsum shiny brown ; venter brown with a Avhite spot on each side of pedicel, a Avhite mark behind epigas- tric groove, brown ring around spinnerets, and a small white mark on each side of ring around spinnerets. Sides and clypeus of carapace punctate, dorsum almost smooth. Median eyes on stalk; lateral eyes on tubercles (Fig. 2). Anterior median eyes larger than others, slightly less than a diameter apart. Poste- rior median eyes one and one-half diameters apart. Sternum LKVI : AMKRICAN 1' I lOIJOXClDlA 71 punctate. Dorsum of abdomen heavily selerotized, domed, with paired slight depressions; venter folded with many sclerites (Figs. 3-5). Total length l.fi mm. Carapace 0.8 mm long, 0.6 mm wide. First patelhi and tihia, 0.4 mm; second, 0.3 mm; third, 0.8 nnn. Fourth femur, 0.4 mm; ])ate]]a and tibia, 0.5 mm; metatarsus, 0.2 nnn; tai-sus, 0.2 mm. Diagnosis. The shape of the carapace (Fig. 2) and color of the abdomen separate P. ntoyohamha from P. ruhroniaculata. The palpus (Fig. 1) has a shorter embolus than P. longiceps. The palpus resembles that of some species of Dipocna, but only determination of the number of female seminal receptacles will make the generic affiliation certain. Phoroxcidia studo sp. n. Figures 6-11 Type. Female holotype from Sao Paulo de Olivenca, Ania- zonas, Brazil (M. de Mathan), in the Museum National d'llis- toire Naturelle, Paris (No. 8329). The specific name is an arbi- trary combination of letters. Description. Carapace dark brown with posterior central por- tion lighter brown ; sternum, legs dark brown. Abdomen dark brown, sclerites darker, a Avliite pigment ring around lateral edge on venter (Figs. 9, 10), and some white pigment spots be- hind epigynum. Carapace tuberculate on sides. Median eyes on projection and each two lateral eyes on a tubercle (Fig. 6). Anterior median eyes slightly larger than others, their diameter apart. Posterior median eyes their diameter apart. Dorsum of abdomen with trapezoidal sclerites, venter also with sclerites (Figs. 9-11) . ^lost sclerites with darker spot in middle and double bordered. Total length 2.1 mm. Carapace 0.9 mm long, 0.7 mm wide. First patella and tibia 0.5 mm ; second 0.4 mm ; third, 0.4 mm. Fourth femur, 0.6 mm ; patella and tibia, 0.6 mm ; meta- tarsus, 0.3 mm; tarsus, 0.3 mm. Diagnosis. The unusual shape and arrangement of the sclero- tized plates readily separate this species from all other PJwron- cidia. I suspect that this is the female of Phoroncidiu longiceps. known only from a male. A juvenile male collected in Peru has its abdomen like that of the female but the mc^dian eye region projects farther anteriorly. Records. Peru. Hiianiico: Divisoria, Sept., Oct. 1946, 1 juv. S (F. Woytkowski, AMNH). Brazil. Amazonas. Sao Paulo de Olivenca, 9 paratype (M. de ^Mathan, MNIIN). 72 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY Phoroncidia longiceps (Keyserling), n. comb. Figures 12-17 Wibrada longiceps Keyserling, 1886, Die Spiiinen Amerikas, Tlieridiidae, 2(2): 22, pi. 11, fig. 145, $. Male holotype from "Peru," in the Mu- seum National d'Histoire Naturelle, Paris, examined. Vibrada longiceps, — Simon, 1894, Histoire Naturelle des Araignees, 1 : 560, fig. 570. Note. Keyserling 's locality is in error since the specimen is marked as coming from Le Para [Belem, Brazil] and was col- lected by M. de Mathan. Simon (1894) indicated that the speci- men came from the Amazon region of Brazil. Keyserling ap- parently misread Peru for Para on the label. Bescripiion. Carapace dark brown, the portion covered by abdomen lighter. Sternum, legs dark brown. Dorsum of abdo- men dark brown ; venter with selerotized areas dark brown but a ring of white pigment between dorsal and ventral scuta (Figs. 15, 16). Carapace tuberculate on sides; sternum tubercu- late. Anterior median eyes slightly larger than others, their diameter apart. Posterior median eyes their diameter apart. Median eyes projecting (Figs. 12, 13), and laterals on a hump. Chelicerae with small fangs. Abdomen with a dark dorsal shield that has impressions of trapezoids; in the center of each is a dark spot (Figs. 15, 17). Total length 1.6 mm. Carapace 0.9 mm long, 0.7 mm wide. First patella and tibia, 0.4 mm ; second, 0.3 mm ; third, 0.3 mm. Fourth femur, 0.5 mm ; patella and tibia, 0.5 mm ; metatarsus, 0.2 mm ; tarsus, 0.2 mm. Judging by the trapezoid dorsal impressions and the trapezoid plates on dorsum of the abdomen, P. siiido may be the female of P. longiceps. Phoroncidia rubromaculata (Keyserling), n. comb. Figures 21-23 Herihertus ruhromaculatus Keyserling, 1886, Die Spinnen Amerikas, Tlieri- diidae, 2(2): 28, pi. 11, fig. 148, $. Fragments of male type from [Nova Friburgo, Est. Eio de Janeiro] Brazil, in the Museum National d'Histoire Naturelle, Paris, examined. Ulesanis rubromaculata, — Simon, 1894, Histoire naturelle des Araignees, 1: 554. Note. Keyserling described the species from "Brazil." The label in the type vial indicates that the specimen came from "N. Friburgo." Both palpi and most legs of the holotype are missing. LEVI: AMKincAX I 'HOK'ONM IDIA 73 Description. Carapace d;irk hi'owii. Sicrnuiii. Ic^-s brown. Selerotized ]nirt of abdomen bi'owii, dorsum with a median white mark, Avliich is longer than wide and was pr()l)ably i-eddisli in the live spider (Fig. 23). Eyes subequal in size. Antei-ior me- dian eyes one and one-half diameters apart, two and one-lialf diameters from laterals. Posterior median eyes one and one-half diameters apart, one and thi'ee-(iuarters diameters from laterals. Eye region of carapace high and projecting anteriorly (Fig. 21). Abdomen with heavily selerotized dorsal shield having some darker marks. Venter with numerous selerotized areas (Figs. 21, 22). Total length 2.1 mm. Carapace 1.0 mm h)ng, 0.8 nun wide. First femur, 0.7 iiini. Second patella aiul tibia. 0.5 mm. PnoRONCiDiA scuTULA (Nicolet), n. comb. Figures 18-20 (htstcracantha scutuJa Xicolot, 1849, ('« Gay, Histoiia de Cliile, Zool., 10(3): •i78, pi. 5, fig. 6, ? . Female type from Chile lost. Gasteracantlia caduceator Nicolet, 1849, op. cif., p. 479. Female type from Chile, lost. Gasterucantha violaccata Xit-olet, 1849, op. cit., p. 479. Female type from Chile, lost. Gasteracantlia porcellanac Xicolet, 1849, op. cit., p. 480. Female type from Cliile, lost. Gasteracantlia maculata Xicolet, 1849, op. cil., p. 480. Female type from Chile, lost. Gasteracantlia rcnusta X'icolet, 1849, op, cit., p. 480. Female type from Chile, lost. Gasteracantlia ventrosa Xicolet, 1849, op. cit., yi. 481. Female type from Chile, lost. Gasteracantlia scitida Xicolet, 1849, op. cit., p. 481. Female type from Chile, lost. Gasteracantlia inflata Xicolet, 1849, op. cit., p. 482. Female type from Chile, lost. Gasteracantlia columnata X'icolet, 1849, op. cif., p. 482. Female type from Chile, lost. Gasteracantlia punclata Xicolet, 1849, op. cil., p. 483. Female type from Chile, lost. Gasteracantlia minuta Nicolet, 1849, op. cit., j). 483. Female type from Chile, lost. Ulesanis scutula, — Keyserling, 1886, Die Spiniien Amerikas, Theridiidac. 2(2) : 18, pi. 11, fig. 14, 9. — Tullgren, 1902, Bih. Svenska Yet. Akad. Handl., 28(4): 16, fig. 5, i. Bonnet, 19r)9, Bibliograpliia Araiioorum, 2:4753. 74 BULLETIN : MUSEUM OP COMPARATIVE ZOOLOGY Note. Keyserling first synonymized Nieolet's Gasteracantha species. According to Keyserling the abdomen of the female is like that of the male. Description. Male. Carapace dark grayish brown. Distal end of labium and maxillae white. Sternum dark gray-brown. Legs dark brown except coxae and tarsi white. Abdomen black with white spots on dorsum or sides, no two specimens alike. Sclero- tized parts very dark brown. Carapace highest in thoracic re- gion (Fig. 19). Anterior median eyes slightly larger than others, their diameter apart and one diameter from laterals. Posterior median eyes two-thirds diameter apart, one and one- quarter diameters from laterals. Abdomen dorsum covered by a sclerotized, punctate scutum, with a dorsal hump (Figs. 19, 20). Sclerotized plates and spots on sides ; epigastric area heavily sclerotized and sclerotized ring around spinnerets. Total length 1.8 mm. Carapace 0.9 mm long, 0.8 mm wide, 0.4 mm high. First patella and tibia, 0.6 mm ; second, 0.5 mm ; third, 0.4 mm. Fourth femur, 0.6 mm ; patella and tibia, 0.7 mm ; metatarsus, 0.3 mm ; tarsus, 0.3 mm. Older males have the abdomen more wrinkled ventrally than younger ones. Records. Bolivia. Beni: Rurrenabaque, 10 Nov. 1956, $ (L. Peiia, ISNB). Chile. Valdivia: Enco, 3 March 1955, $ (L. Peiia, ISNB). Llanquihue: Carelmapu, 21-28 Feb. 1961, $ (L. Pena, ISNB). Aysen: Upper part of Aysen Valley, $ (P. Du- sen, RMS). Phoroncidia AMERICANA (Emcrtou) Map Ulesanis americana Emerton, 1882, Trans. Connecticut Acad. Sci., 6: 28, pi. 6, fig. 1, 9 , $ . Female, male syntypes from New Haven, Connec- ticut, in the Museum of Comparative Zoology, examined. — Bonnet, 1959, Bibliographia Araneorum, 2:4751. Oronota americana, — -Levi, 1955, Ann. Ent. Soc Amer., 48; 334, figs. 1-8, ?, $. Distribution. Eastern Canada, eastern United States, Cuba, Jamaica. (Map.) Adclitional Records. Canada. Nova Scotia: Coldbrook, 31 Aug. 1955 (C. Dondale). Ontario. ]\Iarten River, 36 mi. N of North Bay, 31 Aug. 1955 (II., L. Levi). United States. Michi- gan. Crawford Co.: Hartwick Pines, Sept. 1955 (II., L. Levi). I.KVI : AMKKICAX IM I()R( )X(II)|.\ 75 Arkansas. Washino:toii Co.: Cove Creek \';illcy, 15 mi. W of Prairie Grove; Boston Mts., 300 m (0. llitej. Jamaica: Ilai-d- war Gap, 5 Dec. 1954, $ (A. M. Nadler, AMNIT). Distriljution of Pltoroncidia antrriccnia. PhORONCIDIA NICOLETI sp. 11. Figures 24-26 Type. Male holotype from Sierra cle Chilian, Chilian, Chile, in the Museum National d'Histoire Naturelle, Paris (no. 17()99). The species is named after the early French arachnologist H. Nieolet. Descripfioit. Carapace brown with indistinct pray marks radiating- to sides. Sternum brown. Legs brown with distal seg- ments lighter. Abdomen dark gray with a narrow dorsal light crescent, underlain by white pigment, with its arms pointing posteriorly (Fig. 26). Ring around spinnerets darker gray. Carapace only slightly overhanging eye region. Eyes subequal in size. Anterior eyes their diameter apart. Posterior medians 76 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY one and one-quarter diameters apart, two-thirds diameter from laterals. Abdomen Avith two posterior pointing projections (Figs. 25, 26), cornicnlate, except for smooth area of white crescent. Total length 1.6 mm. Carapace 0.7 mm long, 0.7 mm wide. First femnr, 0.7 mm ; patella and tibia, 0.6 mm ; metatarsus, 0.4 nnii ; tarsus, 0.3 nnn. Second patella and tibia, 0.5 mm; third, 0.4 nnn; fourth, 0.6 mm. Diagnosis. The two projections of the abdomen (Figs. 25, 26) distinguish this species from P. scufida, and the lack of dorsal tubercles from P. coquimo. Phoboncidia ravot sp. n. Figures 27-29 Type. Male holotype from Tovar, Aragua, Venezuela, 1888 (E. Simon), in the Museum National d'Histoire Naturelle, Paris (no. 10171). The specific name is a noun in appo.sition, an ana- gram of the type locality. Description. Carapace dark brown, sternum brown, legs yel- low-brown. Abdomen dark brown except for two pairs of white spots on dorsum, a large white patch on each side above spin- nerets, and a white patch on each side of the venter anterior to pedicel above carapace. Carapace with median eyes on pro- jection and laterals on a slight hump. Eyes subequal in size. Anterior median eyes one diameter apart. Posterior median eyes one and one-half diameters apart, about three diameters from posterior laterals. Abdomen subtriangular with a median dor- sal posterior spine (Figs. 27, 29). Dorsum covered with in- numerable small sclerotized discs ; some elongate plates on ventral part of sides and venter with some round plates and spots between epigastric groove and sclerotized ring surround- ing spinnerets. Total length 2.0 mm. Carapace 1.0 mm long, 0.8 mm wide. First patella and tibia, 0.6 mm ; second, 0.4 mm ; third, 0.4 mm. Fourth femur, 0.6 mm ; patella and tibia, 0.6 mm ; metatarsus, 0.3 mm ; tarsus, 0.3 mm. Diagnosis. The well-sclerotized palpus has the embolus al- most straight, unlike any other Phoroncidia examined (Fig. 28). It is possible that this is the male of P. gira collected at the same locality, and having a triangular abdomen. Records. Venezuela. Aragua: Tovar, 2 juv. paratvpes, 1888 (E. Simon, MNHN). LKVI : AMKHICAX I'l lOKO.XCIDIA 77 PlIOHONCIDIA MARGAMARGA Sp. II. Figures 30-34 Type. Female holotypc from Marga. Maf^vi, \'alparaiso Prov., Chile, 11-13 Sept. 1054 ( L. Pcna), in the liistitnt Poyal des Sciences Xalurellcs de B('l^i({iie, Brussels. Tlic six-cific name is a noun in apposition after the type locality. Description. Carapace dark brown, eye r('s and posterior black; a dark brown ring around spiinierets and white between. Anterior median eyes slightly larger than others; two- thirds diameter apart, two diameters from laterals. Posterior median eyes one and one-half diameters apart, two diameters from laterals. Abdomen with three spines (Figs. 79-81), sclero- tized discs, and variable nnmbei- of tiny sclerotized spots. Total length of females 3.3-5.0 nun. Total length of one female 4.6 mm. Carapace 1.3 mm long, 1.3 mm wide. First ])atella and tibia. 1.0 mm; second. 0.8 mm; third, 0.7 mm. Fourth femur, 84 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 1.1 mm; patella and tibia, 1.3 mm; metatarsus, 0.6 mm; tarsus, 0.5 mm. Drawings Avere made from a recently collected specimen from Nova Teutonia. Diagnosis. The single median opening in the epigynum (Fig. 78) distinguishes the species from P. tricuspidata. Records. Brazil. Est. Sao Paulo: Fazienda Novo-Niagara, lat 23° 00' S, long 49° 20' W, 1898, 9 (E. Gounelle, MNHN). Santa Catarina: Nova Teutonia, lat 27° 11' S, long 52° 23' W, ? (F. Plaumann, SMF). Phoroncidia gira sp. n. Figures 82-86 Tifpe. Female holotype from Tovar, Aragua, Venezuela, 1888 (E. Simon) in the Museum National d'Histoire Naturelle, Paris (no. 10025). The specific name is an arbitrary comliination of letters. Description. Carapace, sternum brown, legs lighter brown. Abdomen with three orange-colored spines, dorsum white except for dark brown sclerotized discs and spots; venter white on sides, but area between epigynum and spinnerets on sides of pedicel without pigment. Eyes subequal in size. Anterior me- dian eyes one diameter apart, one and one-half diameters from laterals. Posterior median eyes one and one-cjuarter diameters apart, two diameters from laterals. Abdomen with three spines, large, dark discs and smaller sclerotized spots on dorsum and venter. Total length 5.7 mm. Carapace 1.3 mm long, 1.4 mm wide. First patella and tibia, 1.0 mm; second, 0.5 mm; third, 0.5 mm. Fourth femur, 1.3 mm; patella and tibia, 1.3 mm; metatarsus, 0.6 mm ; tarsus, 0.5 mm. Diagnosis. The epigynum has a posterior median dark de- pression with an indistinct dark spot in each side of it (Fig. 83). The region posterior to the depression is heavily sclerotized. The connecting ducts are hardly visible in the cleared female genitalia (Fig. 82). The structure on the epigynum and the relatively long abdominal spines se]iarate the species from P. triunfo and /*. tricuspidaia. KEFERENCES Hickman, V. V. 1951. New I'horoncidiinao and the afliiiitios of the Now Zealand spider Atkinsonia ikiiki ('aiiiliridg'e. Paiu'is Proc. Roy. Soe. Tasmania. 1950: 3-'J4. LEVI: AMERICAN PIIOROXCIDIA 85 Levi, H. W. 1955. The spider genera Oronota and Sttiitinoji.s in North America, Central America and the West Indies (Araneae, Theridiidae). Ann. Ent. Soe. America, 48f.l): 333-342. Levi, H. \V. and L. R. Lfai 19(5:2. The genera of the spider- family Theridiidae. Bull. .Mas. Conip. Zoul., 127(1): 1-71. (lieceived May 13, 19G3.) 86 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY INDEX Valid names are printed in italics. albopum-tata, Trieantha, (59 aniericana, Oronota, 74 americana, PJioroncidiii, 74 anierieana, Ulesanis, 74 biocellata Phoroncidia, 81 biocellata, Trieantha, 81 caduceator, Gasteracantha, 73 columnata, Gasteracantha, 73 coqidmho, Phoroticidia, 77 cribratci, Phoroncidia, 79 eribrata, Trithena, 79 flavolimhafa, Phoroncidia, SI flavolimbata, Trieantha, 81 flavomaculata, Ulesanis, 68 gira, Phoroncidia, 84 inflata, Gasteracantha, 73 inuneans, Trieantha, 80 longiceps, Phoroncidia, I'l longiceps, Wibrada, 70, 72 maculata, Gasteracantha, 73 margamarga, Phoroncidia, 77 niinuta, Gasteracantha, 73 niojiohaniha, Phoroncidia, 70 nicoleti, Phoroncidia, 75 poreellanae, Gasteracantha, 73 punctata, Gasteracantha, 73 ravot, Phoroncidia, 76 reimoseri, Phoroncidia, 83 ruhromaculaia, Phoroncidia, I'l rubroniaculata, Ulesanis, 72 saboya, Phoroncidia, 82 scitula, Gasteracantha, 73 scutelhita, Pltoroncidia, 79 scutellata, Trieantha, 79 scutula, Gasteracantha, 73 scutula, Phoroncidia, 73 scutula, Ulesanis, 73 studo, Phoroncidia, 71 Una, Phoroncidia, 78 tricornis, Trieantha, 80, 82 tricuspidata, Phoroncidia, 80 tricuspidata, Plectana, 80 triunfo, Phoroncidia, 82 ventrosa, Gasteracantha, 73 venusta, Gasteracantha, 73 violaeeata, Gasteracantha, 73 PLATES BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY Figs. 1-5. Phoroncidia moyohamha sp. n., male. 1. Left palpus. 2. Cara- pace. 3. Lateral view. 4. Abdomen, ventral view. 5. Abdomen and cara- pace, dorsal view. Figs. 6-11. P. .studo sp. n., female. 6. Carapace. 7. Genitalia, dorsal view. 8. Epigynum. 9. Abdomen, ventral view. 10. Lateral view. 11. Carapace and abdomen, dorsal view. Figs. 12-17. P. longiceps (Keyserling), male. 12, 1.3. Carapace. 14. Pal- pus. 15. Lateral view. 16. Abdomen, ventral view. 17. Carapace and ab- domen, dorsal view. LEVI: AMERICAN* IM lOKOXCIDIA BULLETIN : MUSEUM OF COMPARATIVE: ZOOLOGY Figs. 18-20. Plioroncidia scntula (Nicolet), male. 18. Left palpus. 19. Lateral view. -0. Carapace and abdomen. Figs. 21-23. P. rubromaculata (Keyserling), male. 21. Lateral view. 22. Sternum, coxae and aljdonien, ventral view. 23. Carapace and abdomen, dorsal view. Figs. 24-26. P. nicolcii sp. n., male. 24. Palpus. 25. Lateral view. 26. Carapace and abdomen, dorsal view. Figs. 27-29. P. ravot sp. n., male. 27. Lateral view. 28. Palpus. 29. Cara- pace and abdomen, dorsal view. LEVI: AMERICAX rilOROXCIOIA BULLETIN : MUSEUM OP COMPARATIVE ZOOLOGY Figs 30-34. PJioroncidia margamarga sp. n., female. 30. Genitalia, dorsal view. 31. Epigynuni. 32. Lateral view. 33. Sternum, coxae and abdomen, ventral view. 34. Dorsal view. Figs. 35-37. F. Una sp. n., male. 35. Left palpus. 36. Lateral view. 37. Carapace and abdomen, dorsal view. Figs. 38-41. P. eoquimbo sp. n., female. 38. Genitalia, dorsal view. 39. Epigynum. 40. Lateral view. 41. Carapace and abdomen, dorsal view. LEVI : AMERICAN PIIOROXCiniA BULLETIN : MUSEUM OP COMPARATIVE ZOOLOGY Figs. 42-45. Phoroncidia scutellata (Taezanowski), female. 42. Genitalia, dorsal view. 43. Epig.viium. 44. Lateral view. 45. Dorsal view. Figs. 46-51. P. tricuspidata (Blackwall), female, 46. Genitalia, dorsal view. 47. Epigynum. 48. Lateral view. 49. Al)domen, ventral view. 50, 51. Carapace and abdomen, dorsal view. Figs. 52-56. P. crihrata (Simon), female. 52. Genitalia, dorsal view. 53. Epigyniim. 54. Lateral view. 55. Sternum, coxae and abdomen, ventral view. 56. Carapace and abdomen, dorsal view. LEVI: AMKKUAX I'l lOKOXClDlA 43 ^•^?i",'£5fS3?lK5s-^,, 53 BULLETIN : MUSEUM OF COMPARATRTi ZOOLOGY rig«. 57-61. Phoroncidia flavolimhata (Simon), female. 57. Genitalia, dorsal view. 58. Epigynum. 59. Lateral view. 60. Sternum, coxae and ab- domen, ventral view. 61. Carapace and abdomen, dorsal view. Figs. 62-65. P. triunfo sp. n., female. 62. Genitalia, dorsal view. 63. Epi- gynum. 64. Sternum, coxae and abdomen, ventral view. 65, 66. Carapace and abdomen, dorsal view. 65. Adult. 66. Juvenile. Figs. 67-71. P. hiocellafa (Simon), female. 67. Genitalia, dorsal view. 68. Epigynum. 69. Lateral view. 70. Sternum, coxae and alxlomen, ventral view. 71. Carapace and abdomen, dorsal view. LKVI : AMERICAN I'lIOROXCIDIA 58 _;;?*wa>v/;.;'' 'i^!4,' ■ 63 .••..^;iSS^^fe. BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY Figs. 72-76. Phoroncidia sahoi/a sp. n., female. 72. Genitalia, dorsal view. 73. Epigynum. 74. Lateral view. 75. Abdomen, ventral view. 76. Carapace and abdomen, dorsal view. Figs. 77-81. P. reimoseri sp. n., female. 77. Genitalia, dorsal view. 78. Epigynum. 79. Lateral view. 80. Sternum, coxae and alidomen, ventral view. 81. Carapace and abdomen, dorsal view. Figs. 82-86. P. gira sp. n., female. 82. Genitalia, dorsal view. 83. Epi- gynum. 84. Lateral view. 8.5. Sternum, coxae and abdomen, ventral view. 86. Carapace and abdomen, dorsal view. i,i;vi : AMi.incAx i'iioi;()X( iDiA Bulletin of the Museum of Comparative Zoology II A R V A K 1) UNIVERSITY Vol. 131, No. 4 THE BRAINCASE OF THE PALEOZOIC ELASMOBRANCH TAMIOBATIS By Alfred Sherwood Romer With One Plate CAMBRIDGE, MASS., U.S.A. PRINTED FOR THE MUSEUM April 30, 1904 Publications Issued by or in Connection WITH THE MUSEUM OF COMPARATIVE ZOOLOGY HARVARD UNIVERSITY Bulletin (octavo) 1863 — The current volume is Vol. 131 . Breviora (octavo) 1952 — No. 203 is current. Memoirs (quarto) 1864-1938 — Publication terminated with Vol. 55. JoHNSONiA (quarto) 1941 — A publication of the Department of Mollusks. Vol. 4, no. 41 is current. Occasional Papers of the Department of Mollusks (octavo) 1945 — Vol. 2, no. 28 is current. Proceedings op the New England Zoological Club (octavo) 1899-1948 — Published in connection with the Museum. Publication terminated with Vol. 24. The continuing publications are issued at irregular intervals in num- bers which may be purchased separately. Prices and lists may be obtained from the Publications Office of the Museum of Comparative Zoology, Cambridge 38, Massachusetts. Peters' Check-List of Birds of the World. Volumes 1. 4 and 6 are out of print ; volumes 2, 3, 5, 7, 9, 10 and 15 are currently available. Phylogeny and Evolution of Crustacea. Proceedings of a confer- ence held at Cambridge, Mass., March 6-8, 1962. H. B. Whittington and W. D. I. Rolfe, editors. Cambridge, Mass., 192 pp., 80 figs., 1963. Cloth bound, $6.75. Fishes of the Gulf of Maine, by Henry B. Bigelow and William C. Sehrooder. AVashington. viii -577 pi).. ID.':}. Plioto-offsot rcin-int. .$6.50. Publications of the Boston Society of Natural History The remaining stock of the scientific periodicals of the Boston Society of Natural History has been transferred to the Museum of Comparative Zoology for distribution. Prices for individual numbers may be had upon request. Bulletin of the Museum of Comparative Zoology HARVAKU UNIVERSITY Vol. 131, No. 4 THE BRAINCASE OF THE PALEOZOIC ELASMOBRANCH TAMI0BATI8 By Alfred Sherwood Romer With One Plate CAMBRIDGE, MASS., U.S.A. PRINTED FOR THE MUSEUM April, 1964 Bull. Mus. Coiiip. /()()!., llarv.-ird Uiiiv., 131(4 1:87-1(1.'), Ai)ril, 1964 No. 4 — The Braiiicas( of the ralcozoic Kldsniobranch Taiuiobatis By Alkhi:i) Siieuwood Ko.mkk INTRODUCTION Eastman in 1897 described, as Tamiohatis. rrfiisliis, a sjioci- mcii fj'oiii Powell Connty, Kentucky, enelosed in a limestone nodule, wliicli he heliexcd to exhibit the dorsal surface of the braincase of a Devonian skate. However, the age of the specinuui is uncertain ; it is not a skate ; it is the ventral, rather than the dorsal surface of the braincase that is exposed. In consequence, Eastman's structural identifications are quite erroneous. The Tamiohatis type is, nevertheless, of considerable importance, for it is the best preserved specimen of a Paleozoic elasmobranch braincase so far described. A few Paleozoic forms are repre- sented by crushed slab materials in which little morpholooical detail can be made out. But of three-dimensional Paleozoic shai-k braincases, there have been described only two imperfect speci- mens. These ar(^ partial, late Devonian braincases, ju'esumably of ''Cladodii.s" type (Stensio, 1937; Gross, 1937 ).i Some years ago I was struck by the obvious resemblance of Tamiohatis to the pleuracanth l)raincases which T was then studying'. The specimen (I^SXM No. 1717) was loaned to me through the courtes.v of the Division of Vertebrate Paleontology of the United States National Museum. In earlier years com- plete development of the specimen would have been extremely difficult ; thanks, however, to the newer methods of acid prepa- ration developed at the British Museum by H. A. Toombs and A. E. Rixon, the limestone nodule has l)(>en comj^letely etched aAvay Avithout harm to delicate surface sti'uctures of the brain- case. Preparation was done Avith the aid of a National Science Foundation grant for study of Carboniferous vertebrates. I had originally planned to defer description of this specimen until after ]niblication of work on the structure (internal as well as external) of the pleuracanth braincase. But since it currently appears that this study will not be completed for some time to come, I am Dublishiug th(^ present account, despite the fact that incomplete knowledge of the intenuil structure of lA further Paleozoic shark braincaso is (nirrrntlv I)oing stiuliod by Dr. D. II. Dunkle of the U. S. National Museum. 90 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY older elasmobranch braincases may cause misinterpretation of the nature of foramina and other external features. In the description below I have made no reference to East- man's original description, since his belief that the originally exposed surface was dorsal rather than ventral invalidates his identifications. Thus, for example, the canals for the aortaB are identified by him as endolymphatic ducts, the pituitary fossa is said to be a dorsal fontanelle, the interorbital region is labelled rostrum, and the postorbital and otic processes are described as antorbital and postorbital processes, respectively. Provenance of the Specimen No data concerning the discovery of this specimen have been preserved in the records of the U. S. National Museum beyond the statement that it was found in the eastern part of Powell County, Kentucky. As may be seen from a geological map (Jillson, 1929), this small county includes strata ranging from Silurian at its western margin to lower Pennsylvanian (Potts- ville) on the ridge-tops to the east. However, the stratigraphic possibilities can be readily narrowed down. On the one hand, the Pennsylvanian beds are continental shales and sandstones, and it is practically out of the question that a limestone nodule containing marine vertebrates could have been derived from them. On the other hand, Silurian and most Devonian beds are confined to the western part of the county, and the only De- vonian strata reaching the eastern part of Powell County are the black shales of the late Devonian, in which (again) occur- rence of a limestone nodule of this sort is most unlikely. Considerable work in this general area is being done at the present time by the U. S. Geological Survey. It is the opinion of those familiar with the region that the specimen rather surely came from early Mississippian limestones present in eastern Powell County. Possibly a closer determination can be made when current studies of the region are completed. DESCRIPTION General. The general appearance of the braincase is readily seen in the illustrations. The surface of the cartilage was calci- fied to the extent of a millimeter or so. The calcified areas are dark in color; over a considerable area of the ventral surface, exposed before collection, the calcified material has been eroded. ROMKR: TA.MIOBATIS UHAINCASE 91 leaving a cast of the uii(lerlyiiie. Such areas are left white in the plat(>. The os- sibly post-mortem) at mid-length. Posteriorly this ti-ough, Avhich obviously carried the vena capitis lateralis, opens laterally some- what short of the end of the otic region. Above the level of the trough and just behind the postorbital process a well-developed foramen opens outward and backward. This is undoubtedly the opening for the facial nei've. An ojiening ])o.steroventi"al to this is perhaps for a middle cephalic vein. Farther posteriorly there are, on both sides of the specimen, two oval unealcified areas on the iinier wall of the fossa. T cannot interpret them as being to any degree functional; they are too far anterior for either to be reasonably interpreted as for nerve IX. Posteriorly, on either side, the otic region expands laterally into a prominent lateral otic process. The dorsal surface of the process is for the most part gently convex; its proximal part was presunuibly underlain l»y th(> posterior end of the horizontal semicircular canal. Close to its anterior end is a tiny dorsal RO.MKR: TA.MI015ATIS HIiAIXCASE 97 foraiiK'ii which may have carried sonic coinponeiit — ?somatic — of tlie IX-X nerve complex. The distal end of the process and the distal ])art of its anterior margin terminate in thin blunt ridges which woiihl appeal- to have been articidar in nature, ])erhai)s having contact with some anterior meml)er or members of the gill arch series of cartilages. The anterodistal terminus of Ihe ])i'()ces.s is lilted prominently upward. A vei-y considci-abh' part of the anterior face of the lateral otic process is lacking in calcification; this area is (piilc ii-reguhir in outline, as may be seen in the figures. But no reason can be adduced for such a prominent lack of chondrification. It is improbable that the condition seen in the specimen was due to post-mortem loss of surface, for this region wa.s not exposed to weath(>ring of the nodule, and despite the irregularity of the "opening" here, closely similar patterns are ])resent on both sides. A.s noted below, the under side of the otic process is deeply undermined posteriorly. On either side, the calcified base of the otic process is se])arated from the basal plate of the I)raincase by a narrow slit in which no calcification is present. Whether this slit existed in life, and represents a persistent marker be- tween otic and occipital cartilages, or whether this is due to post-mortem crushing, is uncertain. Occipital region. This is relatively short, constricted in width posteriorly, and of lesser depth than the otic region. Dorsally, indications of division l)etwen otic and occipital regions are seen in the form of slight ridues which begin, on either side, lateral to the posterior end of the endolymphatic fossa and curve out- ward and backward to the posterior margin of tlie base of the otic processes. Certain of the markings here are apparently l)ost-mortem in nature, but probably represent, in any event, indications of structural weakness at the points of fusion of elements embryologically discrete. (Xo indications of separation of units are visible ventrally. ) Just posterior to a lov\- transverse ridge behind the endo- lymphatic fossa is a large triangular opening, facing dorsally. At first glance one would assume, from its position, that this is the foramen magnum. This, how'evei-. is not the case, but the nature of this opening is unknown. Possilily it merely repre- sents an uncalcified ai-ea in the braincase roof, but against this interpretation is the fact that the opening shows a distinct, if low, boundary ridge. Posterior to this o])ening there is a median 98 BULLETIN : MUSEUM OF COMPAEATIVE ZOOLOGY occipital crest (incompletely preserved in the specimen). Below the posterior termination of this ridge lies the foramen magnum ; this is nearly completely obscured by dorsoventral crushing. The dorsal portion of the occipital segment is relatively narrow, its lateral boundaries curving medially and posteriorly from the posterior margin of the otic processes. This dorsal area, bound- ing laterall}^ the triangular dorsal opening, described above, and the occipital crest, is gently convex in vertical section ; there is present here a small foramen, perhaps for a "spino- occipital" somatic nerve ramus. Farther ventrally the occipital segment is much broader than it is dorsally, its lateral margins curving inward and then back- ward, from a point well out beneath the otic processes. The upper surface of this thin ventral region forms the floor of a cavity of considerable size which extends forward, contracting in width in its course, beneath the main expansion of the otic process and the dorsolateral margins of the occipital segment. This cavity was not explored to its full depth, but surely formed the exit for the vagus nerve and not improbably the glosso- pharyngeal as well. I believe I can make out, in the lateral wall of the cavity near its posterior end, the inner opening of the small foramen in the otic process, mentioned above, which may have carried a small somatic branch of the glossopharyngeal or vagus. The occipital condjde is, as preserved, much broader than high ; it is V-shaped in contour as seen from above or below, and deeply indented centrally, presumably for the notochord. Ventral surface. The ventral surface of the specimen was exposed when found and had been subject to weathering. The light-colored areas shown in the plate are regions in wdiich weathering had removed the thin surface calcification of the braincase floor; except anteriorly the damage was not severe. The ventral surface was essentially flat. In the interorbital region the lateral margins follow the curved line of the shelf underlying the orbit which, as noted earlier, has been destroyed in part by erosion. Behind the postorbital processes the floor broadens greatly, its lateral borders curving ujjward somewhat to form the margins of the trough which carried the vena capitis lateralis. Beyond the otic process there is a moderate constric- tion in width to the margins of the condyle. As suggested by the pattern of erosion, there were slight longitudinal ridges on either side of the midline toward the back; these merged anteriorly. ROMER: TA.MIOHATIS BKAINCASE 99 pop Fig. 4. Ventral view of the braincase; the pituitary region is imperfectly preserved. Abbreviations as in Figure 1. X V2- Posteriorly the braincase extends to a j^reater depth tliaii in typical modern elasniobranchs, for the paired anterior con- tinuations of the dorsal aorta ("common carotids") entered the braincase floor a short distance anterior to the condyle. Well forward in the otic region a pair of openings presumably mark the exit of the carotids from the aortic canals, and, as may be seen from the plate, there is evidence of gi-ooves — presum- ably for internal carotids — leading from these foramina for- ward and medially toward the hypophysial region. Farther forward on each side is a foramen which may have been the point of entrance of the hyomandibular (pseudobranchial) artery. Still farther forward on either side is a further open- ing, from wliich a deep groove leads forward and outwai-d into the oi'bit ; presumably this was for an external carotid. It is unfortunate that almost the entire surface layer of calcified cartilage has been lost in the hypophysial region ; how- ever, it is reasonable to believe that the surface of the matrix essentially follows the surface contours. There was here a large oval depression, which may have contained an open hypophysial pit. Paired indentation.s leading forward from the front end of this depression suggest that the two internal carotids entered the braincase independently here. 100 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY COMPARISONS As noted above, uncrushed Paleozoic elasmobraneh braincase material exists otherwise only in the case of the two late De- vonian specimens of "Cladodus" and the pleuracanth material from the Permian which I am currently studying. The Tamio- hatis type may be compared with these forms. The specimen studied by Stensio (1937) and named Cladodus hassiacus by Gross (1937) includes only the ventral half of the middle portion of the braincase. The roof is nowhere present ; the specimen ends anteriorly without including the front borders of the orbit and terminates posteriorly part way along the otic region. As far as preserved, the general proportions are comparable to those seen in Taniiobatis. The optic nerve, eye stalk, main trigeminal opening, and more dorsal opening for ophthalmic rami are present as in Tamiohatis, but the last two foramina are apparently less developed than in our type. Due to crusliing and erosion, I cannot tell whether or not Taniiohatis had a notch for palatoquadrate articulation {ohf in Stensio 's figure 1) or whether the ventral bloodvessel openings which he figures were present. Stensio has restored the nasal region di- rectly from Chlamydosdachus, but there is no specific reason for assuming that the pattern was of the fashion found in that modern genus. Of the postorbital process only the lower portion was present in his specimen, and, probably as a consecjuence, it appears to be slimmer than in Taniiohatis. Quite surely, had the process been better preserved, there would have been found, as in Taniiobatis and in Gross' specimen, an articular facet for the palatoquadrate, and not improbably a canal of the .sort which I have suggested as carrying the pretrematic ramus of the facial nerve (perhaps the notch which he illustrates at tlie tip of his postorbital process represents the remains of this canal). Stensio in his figure 3 shows, on the left side, two canals emerging poste- riorly from the base of the postorbital process, of which the upper is labelled as for the jugular vein, the lower for the main trunk of the facial nerve. The course indicated for the jugular is in an unusually high j^osition for that vein, and I suggest that witli better material it would be found that (as in Tainiohdtis) it is the ventral canal which carries the lateral head vein and tliat the dorsal opening is that for the facial nerve. As indicated by his figure 5 and the text, the canal region of the ear was incompletely preserved in Stensiii's si)ecimeii. Ap- parently parts, at least, of all tlir-ee canals were present in liis K()Mi;iv: TA.MlOliA'lIS lUvAIXCASE 101 sj)(H*iim'ii. However, they apjx'cir to occupy a slioiM sjiace antoro- posteriorly — much shorter than is llic case in ph'uracanths, Tamiohatis, or (apparently) in Gross' spccinicn of "Cladodus/- This .seeniinji' abbreviation may well be due to ci-ushin(»s whicli underlie tliis trend may be worthy of pursuit. REFEl?EX(i:S Eastman, C. R. 1897. T(i))iiohatis vrtiisl ii.s ; ;i new form of fossil skate. Aiiier. Jour. Si-i., (4) 4: 85-90. Gross, W. 1937. Das Kopf.skolott von Cladodun irildiuii/rn.si.s Jaekel. 1. Teil. Endocraniiini iiml Palnto(iua(lratuni. Seni'krnhergiana, 19: 80-107. HUSSAKOF, L. 1911. The Permian fislies of Nortli America. Carnegie Inst. Wash- ington, luilil. 146: 155-17.J. JiLLSON, W. R. 1929. Geologic map of Kentucky. Kentucky Geological Survey, Frank- fort, Ky. ROMER, A. S. 19oo. Vertebrate paleontology. Chicago, 491 pp. 2nd ed., 1945, 687 pp. 1941. Notes on the crossopterygian hyomandibular and braincase. Jour. Morpli., 69: 141-160. Stensio, E. a. 1937. Notes on tlie endocrnniuni of a Devonian Chidodus. Bull. Geol. Inst. Upsala, 27: 128-144. 194."i. On the heads of certain arthrodires. Kungl. Svenska Vctensk. Handlingar, (3) 22 no. 1: 1-70. Westoll, T. S. 1938. Ancestry of the tetra pods. Nature, 141 : 127-128. Woodward, A. S. 1916. The fossil fishes of the English Wealden and Purbeck forma- tions. Palaeontographical Society, London, volume for 1915: 1-48, pis. I-IX. (Received August 26, 1963) BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY Plate 1. Dor.sal, lateral and ventral views of the type Inaim-ase of Tmniobatis vetustus, as preserved. The height has obviously been reduced by crushing. White areas on the ventral surface are those in which superficial calcification has been removed by erosion. X Vj. Drawn by N. Strekalovsky. Bulletin of the Museum of Comparative Zoology HARVARD UNIVERSITY Vol. 131, No. 5 THE TAXONOMIC STATUS OF HEPTAXODON AND DENTAL ONTOGENY IN ELAS3IODONTOMY8 AND AMBLYRHIZA (RODENTIA: CAVIOMORPHA) By Clayton E. Ray United States National Museum CAMBRIDGE, MASS., U.S.A. PRINTED FOR THE MUSEUM May 25, 1964 Publications Issued by or in Connection WITH THE MUSEUM OF COMPARATIVE ZOOLOGY HARVARD UNIVERSITY Bulletin (octavo) 1863 — The current volume is Vol. 131 . Breviora (octavo) 1952 — No. 204 is current. Memoirs (quarto) 1864-1938 — Publication terminated with Vol. 55. Johnsonia (quarto) 1941 — A publication of the Department of Mollusks. Vol. 4, no. 41 is current. Occasional Papers of the Department op Mollusks (octavo) 1945 — Vol. 2, no. 28 is current. Proceedings of the New England Zoological Club (octavo) 1899-1948 — Published in connection with the Museum. Publication terminated with Vol. 24. The continuing publications are issued at irregular intervals in num- bers which may be purchased separately. Prices and lists may be obtained from the Publications Office of the Museum of Comparative Zoology, Cambridge 38, Massachusetts. Peters' Check-List of Birds of the World. Volumes 1, 4 and 6 are out of print ; volumes 2, 3, 5, 7, 9, 10 and 15 are currently available. Phylogeny and Evolution of Crnstacea. Proceedings of a confer- ence held at Cambridge, Mass., March 6-8, 1962. H. B. Whittington and AV. D. I. Rolfe, editors. Cambridge, Mass., 192 pp., 80 figs., 1963. Cloth bound, $6.75. Fishes of the Gulf of Maine, l)y Henry B. Bigelow and William C. Schroeder. Washington, viii - 577 pp., 1953. Photo-offset reprint, .$6.50. Publications of the Boston Society of Natural History The remaining stock of the scientific periodicals of the Boston Society of Natural History has been transferred to the Museum of Comparative Zoology for distribution. Prices for individual numbers may be had upon request. Bulletin of the Museum of Comparative Zoology HARVARD UNIVERSITY Vol. 131, Xo. 5 THE TAXONOMIC STATUS OF HEPTAXODON AND DENTAL ONTOGENY IN ELAS3I0D0NT0MYS AND AMBLYRHIZA (RODENTIA: CAVIOMORPHA) By Clayton E. Ray United States National Museum CAMBRIDGE, MASS., U.S.A. PRINTED FOR THE MUSEUM May, 1964 liull. Mus. Comp. Zool., Iliirvard I'liiv., 131(5): 107-127, May, 19(34. No. 5 — Tht Taxonomic Status of llcptaxodon and Dental Ontogeny i)i Elasniodontoiny.s and Aniblyrhiza [Rodcntia : Vaviomorpha) By Clayton E. Ray^ United States National Museum INTRODUCTION The affinities of the extinct Puerto Riean eavioinorph, Hep- taxodon hidens Anthony 1917, have been problematical owing to the supposed reduction of cheek teeth to two on either side above and below, with the first strongly dominant. This condition, grossly aberrant for a caviomorph, led some authors to isolate Heptaxodon in its own monotypic family (IMiller and Gidley, 1918, p. 447, followed by Anthony, 1926,*^ p. 130) or subfamily (Anthony, 1917, p. 186 ;' 1918, p. 397). Others have included it in a subfamily (Simpson, 1945, p. 96, followed by Wood, 1955, p. 182) or family (Landry, 1957, p. 59) together with five^ other West Indian genera. If the stated diagnostic characters of Heptaxodon are accepted at face value, association at the familial level with any known genus of caviomorph seems indefensible. The down-grading in taxonomic isolation of Heptaxodon in the more recent works cited above undoubtedly reflects a growing disbelief in the reality of its apparent uniqueness, but it was H. G. Stehlin {in Stehlin and Schaub, 1951, p. 262, followed by Schaub, 1958, p. 736) who first interpreted the genus as a growth stage of Elasmodontomys ohJiquus Anthony 1916. This author arrived at the correct conclusion on the invalid premise that the dominant cheek teeth of Heptaxodon are P|-of Elasmodontomys . X-ray photographs of critical specimens, restudy of all denti- gerous elements of Heptaxodon, Elasmodontomys, and Amhly- rhiza in the collections of the American Museum of Natural His- tory (AMNH) and the Museum of Comparative Zoology (MCZ), and comparisons with developmental patterns in hystricomorphs and in other caviomorphs have shown, as pointed out in detail below, that the anterior cheek teeth of Heptaxodon are DP-|- of Elasmodontomys. This review of the evidence has made pos- sible a better understanding of dental ontogeny in Elasmodon- tomys and AmMyrhiza. 1 This work was completed while the author was Assistant Curator in charge of fossil vertebrates at the Florida State Museum. Universitj- of Florida, Gaines- ville. - Six. if Quemisia, omitted by the al)ove authors, were included in the group, as it has been to the present by all authors who have discussed it. 110 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY A word is necessary here regarding nomenclature of tooth components. Stirton (1935, p. 392) has derived from the tri- tubercular system a terminology for beaver teeth, and Fields (1957, p. 278) has extended it with additions to certain late Miocene dinomyids, pointing out that "the application of these terms does not necessarily imply homology but has been used as a matter of convenience." I have not felt justified in extend- ing to the highly evolved, hypsodont Elasmodontomys a system which ordinarily carries some connotation of homology. Further, the structure of the Elasmodoyitomys cheek tooth is so elegantly simple that it is most conveniently described in neutral geo- metric and numerical terms. Cope (1883, p. 5) has aptly characterized the units of which the cheek tooth of Amblyrhiza is composed as "columns of den- tine inclosed in ... a sheath of enamel," a description equally appropriate for Elasmodontomys. The columns and their sheaths are flattened anteroposteriorly and closely applied to one another, with a small amount of cementum interspersed. Suc- cessive columns are separated by transverse reentrants that pene- trate the full width of the tooth. Each reentrant may be desig- nated as outer or inner depending on whether its deepest proxi- mal extension is labial or lingual. Individual columns and re- entrants may be distinguished by numbering them serially from anterior to posterior in each tooth. The enamel of the anterior wall of each column (and thus the posterior wall of each reen- trant) is much thicker than that of the posterior wall (anterior wall of reentrant) in the upper teeth, and vice versa in the lower teeth. In both upper and lower teeth the free external enamel walls are invariably thick. Much confusion has arisen in de- scribing these teeth as a result of inconsistent reference to either columns or reentrants, and as a result of failure to detect the thin enamel walls, which appear only as hairlines on occlusal surfaces. The occlusal pattern of each column obliquely sec- tioned by wear takes the form of a much flattened ellipse. In some cases, even in long, little-worn teeth some reentrants are not completely penetrant but have their vertex tightly appressed to the adjacent external enamel wall so that it is visible far down the shaft of the tooth through the translucent external wall. In such cases, and in senescent teeth in which the enamel forms a single continuous trace on the occlusal surface, the pattern produced by each column is more appropriately desig- nated a loop. RAY : STATUS OF IIEPTAXODON 111 D('V('l()})nioiit of tlie lower dentition of Elasmodontomijs will be treated first, followed by the less well documented upper den- tition of Elas)iio(]onfo))})js, and that in turn by the fragmentary data on Amhlyvliizn. Length of a given tooth is in all eases a maximum taken parallel to the longitudinal axis of the tooth, in- eluding roots where present. Selection of genera for comparison has been in part dictated by the availability of appropriate ontogenetic stages, and no a priori implication of relationship is intended. I wish to thank Professor Bryan Patterson, who initiated the present study, for generously turning over to me X-rays pre- pared by Dr. Rainer Zangerl of the Chicago Natural History Museum (CNHM) together with the drawings by Mrs. Dorothy Marsh that are reproduced in Figures 1 and 2. I wish to thank also the curators in the Department of Vertebrate Paleontology, American Museum of Natural History (AMNH), who permitted free use of the splendid collection of Antillean caviomorphs accumulated largely by H. E. Anthony; and the curatorial staffs of the mammal departments of the American Museum of Natural History, Chicago Natural History Museum, and Museum of Com- parative Zoology (MCZ) for making available modern compara- tive material. DENTAL ONTOGENY Lo\vER Dentition of Elasmoclontomys Certain critical specimens are described below in detail in order of increasing age, followed by a discussion of development and comparisons with other genera. AMNH 55030 and 55031, and MCZ 10132 have always been regarded as "Hcptaxodon," whereas AMNH 55037, in spite of its DP4, was identified quite correctly as Elasmodontomys. AMNH 55030. Left ramus with DP4 (Fig. lA). Figured by Anthony (1917, pi. 5, figs. 4, 6; 1918, fig. 38C, D, F; 1926, fig. 48C, D, F). Mandibular symphysis open. Bone porous in tex- ture. DP4 with five columns, the first with a small, semi-isolated subsidiary pillar on its anterolingual wall, the pillar unworn, merging with the column at the alveolar border ; the fourth col- umn with a constriction in the middle of its occlusal surface. Occlusal area small ; obviously it would have increased with addi- tional wear. The X-ray photograph shows incipient double roots of DP4 (reflected externally by a bulge on the ventral 112 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY A \M B C D Figure 1. Early ontogeny of the lower dentition in Elasmodontomys obliquus, showing on the left (approximately X I'l) immature left man- dibular rami in lingual aspect, diagramniatieally represented largely on the basis of X-ray photographs, and on the right (approximatey X 2.2) the corresponding DP4 in occlusal aspect. In order of increasing age the specimens figured are: A, AMNH 55030; B, AMNH 55031; C, MCZ 10132; n, AMNH 55037. RAY: STATUS OF IIEPTAXODON 113 border of the horizontal ramus), the crypt for Mi (the thin walls of which are bi-okeii throiifi'h in three places), and tlie base of the ineisive alveolus adjacent to the posterior bordei' of DP4. Leufith of DP4 approximately 1(5 mm. AMNII 55031. Left ramus with DP4 and Mj (Fig. IB). Sj'mphysis open. Bone porous. DP4 with five columns, the first two confluent anterolabially, the last two merf>ing lin) aspects. An- terior is to the right in (A) and (C), to the left in (B) and (D). X 3. yet to attain its greatest area. Breakage at the base makes it impossible to determine the status of root formation. It may be noted here in passing that the relationship of the upper incisor to the cheek tooth row in Amhlyrhiza is grossly different from that described above in Elasmodontomys. As Schreuder (1933, p. 243) has pointed out, the rostrum of Am- hlyrhiza is greatly elongated, with the upper incisor terminat- ing far in advance of P*, not between P^* and M^. I do not 124 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY feel, however, that the similarity between Amblyrhiza and Chin- chilla in this feature is indicative of relationship, for Elasmo- dontomys and Lagostomus have short rostra with the base of the incisive alveolus overlapping and closely approaching P*, respectively. Summary of Dental Ontogeny "H(ptaxodon" represents a protracted early stage in the ontogeny of Elasmodontomys, in which the DP^ constitute the sole or at least dominant functional elements in the cheek tooth series. The elongate occlusal surface wdtli increased num- ber of laminae in the DP^ presumably is correlated "vvith this long period of use. The sequence of eruption, growth cessation, and root formation in Elasmodontomys, and in Aniblyrhiza as far as the meager data show, is DP|, M|, Mf , P-|, M|. The growing tip of the lower incisor extends progressively farther posteriorly with increasing age in Elasmodontomys. The condition in Amtlyrhiza is unknown. The growing tip of the upper incisor in Elasmodontomys lies directly dorsal to DP 4, leaving insufficient space for the development of P^ in that position. P4 develops anterodorsal to the roots of DP-* and anteroventral to the proximal end of the upper incisor. The growing tip of the upper incisor in Amhlyrhiza. lies in the greatly lengthened rostrum, far anterior to the cheek teeth. With the possible exception of the anteriorly displaced P* locus, every feature in the dental ontogeny of Elasmodontomys has been observed in other (non-heptaxodontid) caviomorphs as well. DISCUSSION The West Indian genera Heptaxodon, Elasmodontomys, Am- blyrhiza, Clidomys, Speoxenns, Spirodontomys, and (when it has been considered) Quemisia, have been associated in a single subfamily. Quemisia will be discussed elsewhere. '' Heptaxo- don" is based on juvenile specimens of Elasmodontomys, and is a junior synonym of the latter. I am as yet unprepared to make pronouncements on the poorly known Jamaican forms, Clielomys, Speoxenns, and Spirodontomys, and thus by default prefer to leave them, at least temporarily, in association with the present group. There is little positive evidence to support the association, but neither is there justification for placing RAY: STATUS OF 1 1 KI'TAXODOX 125 them elsowhero in tlie present state of onr kn<)\vled<2:e. Elasmo- dontomys and Amhlyrhiza assuredly are closely related, and fully warrant association at the subfamilial level. This sub- family is best reo:ar(led as a member of the family Dinomyidae, in an arrantrement similar to that proposed by Schanb {in Stehlin and Sehaub, 1951, p. 370), or possibly as a member of a family very close to the Dinomyidae (Wood, 1955, p. 182). FAMILY-GROUP NOMENCLATURE Anthony (1917, p. 186) proposed three monotypic subfami- lies of Chinchillidae, the Amblyrhizinae, Elasmodontomyinae, and Heptaxodontinae, on successive lines of text in that order. Simpson (1945, p. 96) synonymized the three. Althouo'h Simp- son neglected to mention Aml)lyrhizinae explicitly, his inten- tion is clear in that he included Amhlyrhiza in the single re- sultant subfamily, for which he selected the name Heptaxodon- tinae, a choice undoubtedly dictated by his utilization of the name Heptaxodontidae, first considered as a full family by Miller and Gidley (1918, p. 447). If subfamilial names are re- garded as not influencing priority among full familial names, then Heptaxodontidae is the only valid choice. However, under the present International Code of Zoological Nomenclature (1961, Art. 23), all family-group names are regarded as coor- dinate for purposes of priority. In the present case, this con- troversial rule would have made possible the selection of a more satisfactory family name, either Amblyrhizidae or Elasmodon- tomyidae, both names based on older, better known genera, and as subfamilies both having line priority over the name Heptaxo- dontinae. Even so, Simpson, in the capacity of first reviser (International Code, 1961, Art. 24), has determined the relative priority among these simultaneously published names by select- ing Heptaxodontinae as the senior synonym, and Amblyrhizinae and Elasmodontomyinae as the junior synonyms. Thus, Hep- taxodontidae remains the valid name whichever system of pri- ority is invoked. This situation is, unfortunately, not altered by the fact that Heptaxodon hidens Anthony 1917 is a junior synonym of Elasmodontomys ohliquns Anthony 1916. The Inter- national Code (1961, Art. 40) states explicitly, ''w^hen ... a nominal type-genus is rejected as a junior synonym, a family- group name based on it is not to be changed ..." Thus, although there has been heated debate and strenuous disagree- ment on this subject, the rules are clear and ought to be followed. 126 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY The family-group name Heptaxodontinae remains available, and is not to be replaced by the name Amblyrhizinae An- thony 1917 as Schaub {in Stehlin and Schanb, 1951, pp. 96, 370; and 1958, p. 736) has proposed. LITERATURE CITED Anthony, H. E. 1917. New fossil rodents from Porto Rico, with additional notes on Elasviodontomys obUquus Anthony and Meteropsomys insulans Anthony. Bull. Amer. Mus. Xat. Hist., vol. 37, pp. 183-189. 1918. The indigenous land mammals of Porto Rico, living and ex- tinct. Mem. Amer. Mus. Nat. Hist., n.s., vol. 2, pt. II, pp. 329-435. 1926. Mammals of Porto Rico, living and extinct — Rodentia and Edentata. New York Acad. Sei., vol. 9, pt. 2, pp. 97-241. Cope, E. D. 1883. On the contents of a bone cave in the island of Anguilla (West Indies). Smithson. Contr. to Knowl., vol. 25, art. 3, pp. i-iv and 1-30. Fields, R. W. 1957. Hystricomorph rodents from the late Miocene of Colombia, South America. Univ. Calif. Publ. Geol. Sci., vol. 32, no. 5, pp. 273-404. International Code of Zoological Nomenclature. Adopted by the XV In- ternational Congress of Zoology (Ed. N. R. Stoll, Chairman, et al.). 1961, Internatl. Trust for Zool. Nomencl., London, xvii + 176 pp. Landry, S. O., Jr. 1957. The interrelationships of the New and Old World hystrico- morph rodents. Univ. Calif. Publ. Zool., vol. 56, no. 1, pp. 1-118. Miller, G. S., Jr. 1929. A second collection of mammals from caves near St. Michel, Haiti. Smithson. Misc. Coll., vol. 81, no. 9, pp. 1-30. Miller, G. S., Jr. and J. W. Gidley 1918. Synopsis of the supergeneric groups of rodents. Jour. Wash- ington Acad. Sci., vol. 8, no. 13, pp. 431-448. Schaub, S. 1958. Simplicidentata (=:Rodentia). Pp. 659-818, in J. Piveteau (Ed.), Traite Paleont., t. VI, vol. 2, pp. 1-962. SCHREUDER, A. 1933. Skull remains of Amblyrhiza from St. ^Martin. Tijdschr. Nederl. Dierkundige Vereeniging, ser. 3, vol. Ill, pt. 4, pp. 242-266. Simpson, G. G. 1945. The principles of classification and a classification of mam- mals. Bull. Amer. Mus. Nat. Hist., vol. 85, pp. I-XVI, 1-350. BAY : STATUS OF IIEPTAXODON 127 Stehlin, II. G. and S. Schaub 1951. Die Trigonodontie der simplieidentaten Nager. Schweiz. Naturf. Ges., Paliiont. Abh., vol. 67, pp. 1-385. Stibton", R. a. 1935. A review of the Tertiary beavers. Univ. Calif. Publ., Bull. Dept. Geol. Sci., vol. 23, no. 13, pp. 391-458. Wood, A. E. 1955. A revised classification of the rodents. Jour. Mammalogy, vol. 36, no. 2, pp. 165-187. Wood, A. E. and B. Patterson 1959. The rodents of the Deseadan Oligocene of Patagonia and the beginnings of South American rodent evolution. Bull. Mus. Comp. Zool., vol. 120, no. 3, pp. 279-428. (Received December 1962.) Bulletin of the Museum of Comparative Zoology II A R V A R D UNIVERSITY Vol. 131. No. 0 THE SKELETON OF THE LOWEU (AKliOXl KEKOTS LABYKIXTIIODOXT I'lfOLIDOGASTER PISCIFOmils Bv Alfred Siiiii.'wooi) 1\()mi':r With One Plate CAMBRIDGE, MASS., U.S.A. PRINTED FOR THE MUSEUM May 25, 1964 Publications Issued by or in Connection WITH THE MUSEUM OF COMPARATIVE ZOOLOGY HARVARD UNIVERSITY Bulletin (octavo) 1863 — The current volume is Vol. 131 . Breviora (octavo) 1952 — No. 204 is current. Memoirs (quarto) 1864-1938 — Publication terminated with Vol. 55. JoHNSONiA (quarto) 1941 — A publication of the Department of Mollusks. Vol. 4, no. 41 is current. Occasional Papers of the Department of Mollusks (octavo) 1945 — Vol. 2, no. 28 is current. Proceedings of the Nkw England Zoological Club (octavo) 1899-1948 — Published in connection with the Museum. Publication terminated with Vol. 24. The continuing publications are issued at irregular intervals in num- bers which may be purchased separately. Prices and lists may be obtained from the Publications Office of the Museum of Comparative Zoolog}', Cambridge 38, Massachusetts. Peters' Check-List of Birds of the World. A'^olumes 1, 4 and 6 are out of print ; volumes 2, 3, 5, 7, 9, 10 and 15 are currently available. Phylogeny and Evolution of Crustacea. Proceedings of a confer- ence held at Cambridge, Mass., March 6-8, 1962. H. B. Whittington and W. D. I. Rolfe, editors. Cambridge, Mass., 192 pp., 80 figs., 1963. Cloth bound, $6.75. Fishes of the Gulf of Maine, by Henry B. Bigelow and William C. Schroeder. AVashington, viii - 577 pp., 1953. Photo-offset reprint, $6.50. Publications of the Boston Society of Natural History The remaining stock of the scientific periodicals of the Boston Society of Natural History has been transferred to the Museum of Comparative Zoology for distribution. Prices for individual numbers may be had upon request. Bulletin of the Museum of Comparative Zoology HARVARD UNIVERSITY Vol. 131, No. 6 THE SKELETON OF THE LOWER CARBONIFEROUS LABYRINTHODONT PIIOLIDOG ASTER PISCIFORMIS By Alfred Shekwood Romer With One Plate CAMBRIDGE, MASS., U.S.A. PRINTED FOR THE MUSEUM May, 1964 Bull. Mus. Comp. Zool., Harvard Univ., 131(6): 129-159, May, 1964. No. 6 — The Skeleton of the Lower Carhoniferous Lahyrinthodont Pholidojjaster pisciformis By Alfred Sherwood Romer INTRODUCTION Altlioii' importance in the story of tetrapod evolution, our knowledge of their early evolution and radiation is still exceed- ingly fragmentary. On the one hand, we are fortunate in having materials (as yet not fully described) from the late Devonian of East Greenland (Save-Soderbergh, 1932; Jarvik, 1952, 1955) which illustrate a very early phase of amphibian history ; on the other, we have a very considerable knowledge of Permian and Triassie labyrinthodonts. But most of the crucial stages in lahyrinthodont evolution obviously occurred during the Carboniferous, and here our knowledge is distressingly in- complete. A fair amount of material is known from the later Carboniferous — the Pennsylvanian — but is as yet far from adequately described. Poorer still is the situation as regards the earlier — Mississippian — stage of the Carboniferous. A very limited amount of North American material of this age from West Virginia is now known and under description by Hotton and the writer. Otherwise, as reviewed by Watson (1929; cf. Panchen and Walker, 1960, pp. 327-328), Lower Carboniferous labyrinthodonts are known only from a very few specimens from Scotland, and these are mainly of a fragmentary nature. In consequence, the type of Pholidogaster pisciformis Huxley is of unique importance as the only articulated skeleton of a Lower Carboniferous lahyrinthodont described up to the pres- ent time. As noted by Huxley (1862), the specimen, discovered in the Gilmerton Ironstone of the Edinburgh coalfield over a century ago, was originally acquired by Sir Philip Bgerton and the Earl of Enniskillen, "but as, on mature consideration, it appeared to them not to be a fish, it w^as handed over to the British Museum." Huxley described it briefly. Watson, in his 1929 review of Carboniferous labyrinthodonts, gave an account of such anatomical features as could then be made out. Re- cently Mr. A. E. Rixon has further prepared the specimen, re- vealing a considerable amount of new anatomical data, particu- larly as regards the trunk vertebrae, thus rendering further description advisable. 132 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY I wish to thank Keeper Errol I. White for the privilege of stud^'ing this important specimeii. I am grateful for the friendly and helpful reception given me at the British Museum during the course of this work, not only by Dr. White but by other members of the staff, particularly Dr. W. E. Swinton and Mr. Barney Newman. And I am, of course, particularly in- debted to Mr. Eixon for undertaking the preparation of this difficult material. The specimen comes from the Gilmerton Ironstone of Gil- merton, in the Midlothian Coalfield of the Edinburgh region. As noted by Panchen and Walker (1960, p. 328), the horizon is close to the base of the Carboniferous Limestone Series. The only amphibians of greater age, apart from the ichthyostegids of East Greenland, are a few small lepospondyls and the uni- que Oiocratia skull from the underlying Oil Shale Group of the Calciferous Sandstone Series of the Scottish lowlands. The amphibian remains now under study from West Virginia are from horizons near the summit of the Mississippian, and hence later in time of deposition than Gilmerton. DESCRIPTION Huxley's original figure shows the general character of the specimen (his pi. XI, fig. 3), although the artist has taken cer- tain liberties with it (circular objects which he supplied in the head region suggest orbits, but the view here is ventral ; the vertebral column which he pictures in the trunk region was drawn largely from his imagination, not from the material). A more accurate representation is given in my Plate I, A (in which, however, the squamation is omitted) ; details are shown in Figures 1 and 2. The skeleton (BMNH No. 30534) is pre- served on a series of small slabs which for the most part fit together without apparent gaps ; almost the complete animal was present in articulated fashion. Skull, jaws and trunk are seen in ventral view; the tail is seen from the left side. De- composition appears to have set in to some degree before burial, so that most of the belly wall and its armor of scales, broadly visible the length of the trunk, lies mainly to the (morphological) right side of the column. The total length as preserved is 117 cm. As Huxley notes, the specimen was in "a very indifferent state of preservation," and its natural condition was not improved by preparation, a century ago, of a rather crude na- ture. When studied by Watson much of the structure of the ROiMER : LABYRINTIIODOXT IMIOLIDOGASTKR 133 tail and i)(4vie area was visible, as well as the surface of the under side of the head and shoulder region. Mr. Ri.xon's further preparation dealt mainly with the trunk vertebrae and part of the dorsal surface of the head. Since the skull is poorly pre- served and little can be told of the anterior i)art of the body. I shall reverse the customary sequence in description, and begin with the axial skcldon of the tail, leaving skull and jaws to the last. Tail. Nearly the coinpjcte tail is present. Parts of three vertebrae are missing in the gap between the block contaiiung the pelvic region and those containing the rest of the tail, and another somewhat farther back where a surface chip is missing from the block. Allowing for these missing areas, thirty-one eaudals are present back of the position of the presumed sacral vertebra. The tail is comparable in length with that seen in ichthyostegids, on the one hand, and various temnospondyls, on the other, but is shorter than that seen in many primitive reptiles and in the embolomere A^'cheria. It would appear that when the specimen was discovered the slab split in such fashion that the tail was immediately exposed. However, the split ran for the most part through the substance of the vertebrae, so that surfaces of the elements are but poorly seen. The net result is that interpretation of the material is difficult. In the figures, I have endeavored to outline the structures exactly as preserved, resisting the tempta- tion to give subjective restoration of obscure areas. As a result of the ]XJor condition of the material, it is difli- cult to tell which side of the tail we are looking at. On one margin are seen v\'edge-shaped neural arches from whicii neural spine.s slant diagonally backward; on the opposite nuirgin are almo.st identically shaj^ed intercentra and haemal spines. But which is which ? Watson believed that the view was from the left, so that, for example, in my Plate 1, figure A the neural arches and spines lie along the lower margin. My own conclu- sions, based on more evidence than was available to Watson, were at first that the view was from the opposite, right, side, basing my belief on the fact that the posterior trunk vertebrae are seen somewhat to the right of a direct ventral view, and that, hence, one would expect a continuation of this twist on toward the tail. Put the left half of the pelvic girdle lies uppermost and, most especially, the structure of the caudal vertebral ele- ments is reasonably interpretable only from the Watson point 134 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 00 .g s o .2 IS CO t> ^ -^ en ^ a PI • rH • (H o V. o CO ft 'So •«* in 13 S^ >H o 0) *-»3 .s s a ^ p ^ ^ -a 03 o MOW IIOLIDOGASTER 139 from the under side of the entepicondylar repiou by a loiif=fitiidi- nal ridge. Tlie ])oiie, as seen in end view, is considerably thick- ened above this point. There is no ossified ventral articular area for the radius, but there may have been in life a modest carti- laginous extension here. No entepicondylar foramen is seen, but the bone is somewhat crushed in the area Avhere this might be expected. The upper part of the ulna is preserved, and the distal part is represented by an impression. The olecranon was obviously unossified ; the shaft was 22 mm long, the upper end 5 mm wide ; the bone becomes more slender distally and the radial margin is somewhat concave. Much of the radius is present, but the lower part is incomplete, crushed and obscure. The upper articular surface has a width of 7 mm ; the length appears to have been about 24 mm. Pelvic girdle and limb. As AVatson notes, considerable informa- tion can be obtained regarding the pelvic girdle and limb. There is no trace of the right half of the girdle, but the left half is present, its outer surface exposed, and the ilium directed ' ' down- ward" toward the low^er edge of the slab. There is the long posteriorly-directed process of the ilium common to many very primitive tetrapods (further development shows it to be broader than in Watson's figure). The region in which one would expect a dorsal iliac process for articulation with a sacral rib is damaged. Most of the outline of the acetabulum is preserved ; the ischium is nearly complete; the pubis represented only by an impression. Both femora are present, the right running forward morpholo- gically beneath the column, the left turned upward; the left femur is seen in ventral view, the right from an anterodorsal aspect. The right femur as preserved is 46 mm in length, the left 51 mm. The width of the head is about 12 mm, the distal width the same, the slender shaft 5 mm in minimum breadth. The dorsal surface of the head, seen on the right femur, has the common pattern of primitive tetrapods : well-rounded in transverse section, and somewhat convex in outline proximally, the mid-point of the curve somewhat anterior to the line of the shaft. The exposed anterior aspect of the left femur shows the presence of a pronounced internal trochanter, with a distinct longitudinal depression developed along the anterior surface between the trochanter and the shaft proper. Unfortunately, the head region is imperfectly preserved, and little can be said except that there appears to be the usual ventral intertrochanteric fossa, bounded anteriorly by the internal trochanter. Distally, 140 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY typical anterior and posterior condylar regions are readily dis- tinguishable on both femora, the posterior, as always, more prominent. The two condyles are separated dorsally, as generally, by a distinct longitudinal hollow. Ventrally, broad articular faces for the tibia are seen, facing outward and downward at about a 45° angle; the right femur shows that the end of the posterior condyle was (as frequently in labyrinthodonts) un- ossified. The anterior articular surface extends some distance up the shaft. Ventralty a deeply excavated popliteal space is seen, on the right femur, between the two condyles. A low but sharp adductor crest runs proximally up the shaft from the posterior margin of the popliteal space. Presumably it connected proximally with the internal trochanter, but preservation prox- imally is not good. On the w^hole, the femur is of a generalized and primitive type of the sort seen, for example, in the Pap- posaurus femur from the somewhat later Loanhead No. 2 Iron- stone (Watson, 1914) or in Archeria. The right tibia and fibula are seen from the anterior (extensor) aspect. The tibia has a length of 24 mm; the head, somewhat convex in outline, is 7 mm broad ; the shaft contracts to a width of 4 mm, then expands distallj^, where the width of the bone (partially covered by a metatarsal) appears to have been 9 mm. The fibula (as Watson notes) is, as in primitive tetrapods gen- erally, a longer and broader bone than the tibia, with a length of the right element of 28 mm, and widths of head (partially covered), shaft, and distal extremity of 8, 5 and 11 mm, re- spectively. As in labyrinthodonts generally, the distal articular surface curves broadly proximally toward its tibial margin, affording contact, presumably, with a proximal centrale as well as an intermedium. On the left side the tibia is not preserved; the element present is the fibula. Its length (as is that of its mate) is 28 mm. It appears thin because seen from its medial aspect. Distally the medial portion of the articular surface is exposed. As Watson notes, the tarsal region is difficult of determination. The left tarsus has been exposed since his studies. Preserved (partly as impressions) are a large proximal element and three more distally, above the heads of the metatarsals. Possibly these may represent an intermedium and fibulare, fourth centrale and tibiale ; but if so, we must assume that the distal tarsals and more distant centralia have been displaced and were possibly un- ossified. On the right side is a large element which (again) I tend to identify as an intermedium, and several smaller and ROMEK : LABYRINTIIODONT PHOLIDOGASTER 141 rather obscure elements. On either foot three articulated meta- tarsals are present. This count is surely due to accidents of preservation, and not improbably the animal was pentadactyl. The three left metatarsals have lenj^ths as preserved (counting from the fibular margin) of 10, 9 and 8 mm (the second and third reach tlie edge of a fracture in the block and may have been slightly longer). Those of the left side (counting in the same direction) have lengths of 11, 11 and 12 mm. On the left foot a further, incomplete metatarsal is present alon^ide the distal end of the fibula. Both feet appear to be seen from the ventral aspect. The metatarsals are essentially flat and feature- less, but there is a suggestion of a slight dorsal arching of the bones along their lengths. The most medial toe of the right foot originally had three phalanges, with lengths, as seen in Watson's drawing,^ of about 5, 2+ and 1 mm. This toe has been partially removed, to exhibit a proximal phalanx of a second toe, 7 mm long. Beyond this, Watson's figure indicates, there was formerly a second phalanx, about 4 mm in length, and a small terminal element. Ahdominal armor. The ventral armor is well preserved over most of the region between pectoral and pelvic girdles ; its general disposition may be seen in Huxley's figure 1. As typi- cally, the rows of gastralia on either side meet at a sharp angle in the midline. This midline can be traced from a point just prox- imal to the entepicondyle of the right humerus back, roughly parallel to the vertebral column, to a termination anterior to the head of the right femur. Along the anterior part of the trunk the midline lies but 10-16 mm to the right of the exposed vertebral centra; in the "lumbar" region, however, the midline arches to the left, to an extreme of 40 mm from the column, before curving back toward the pelvis. The squamation of the left side curved downward over the vertebrae and ribs. This area was partly destroyed during preparation of the column. The squam- ation of the right side, however, is fully exposed as far as it was preserved in the specimen when collected. Along the anterior part of the column the squamation extends outward l)ut 20-30 mm from the midline, giving the diagonally-directed scale-lines a length of 25-38 mm. It is probable that the narrowness of the squamate area preserved here is due to post-mortem loss. At the middle of the back, breadth of the scale-covered area in- creases, and extends out some 50 mm to the far edge of the slab, 1 The reduction is closer to X % than to the X % given in Watson's legend. 142 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY giving a maximum length of scale rows, as preserved, of about 70 mm. More posteriorly, the width of the scaled area decreases to about 20-25 mm a few centimeters in front of the pelvis ; as preserved, however, the scale rows here slant very strongly back- ward (perhaps due to post-mortem distortion) so that their lengths approach 50 mm. The general pattern of arrangement of the gastralia is seen in Huxley's figure 4. However, his illustration is rather more than "of the natural size," for in general the scales are but about 10-15 mm long. They are essentially oat-shaped, with greatest widths about one-third the length. Their apparent width is less ; posterior to a longitudinal ridge, the surface of each scale is overlapped by its neighbor, so that the average ex- posed width is little over 2 mm. As Huxley shows (but generally to a somewhat greater degree) the ends of the scales overlap their neighbors in the same scale row. The maximum number of scales in a given diagonal row does not appear to exceed ten or so, even in the broadest preserved area of squamation. The central element in each row is roughly U-shaped, with the two arms of the U diverging posteriorly from one another at about 60° ; anteriorly, each median scale sends forward from its rounded central area a tongue-shaped process which underlaps its anterior neighbors. Skidl. The skull has been crushed flat in such fashion that the jaws were pushed somewhat to the right, the skull to the left. A limited amount of the dermal roof is visible on the under surface (Fig. 2). At the "lower" margin is seen a frag- ment containing most of the left jugal. Its posterior end is represented only by an impression, and hence its relation to the quadratojugal is not clear. The ossification center is close to the anterior end of the part preserved. Near the anterior end of the jugal are fragmentary remains of the lower margin of the left maxilla ; a few small teeth are visible. The lower margins of both premaxillae are visible. The teeth are for the most part absent, but nearly the whole length (of about 7 mm) of a large tooth is preserved, and there are obscure remains of several other teeth and alveoli. Lying near the right clavicle is the displaced right quadrate, and a broken strip of bone anterior to it may be the right quadratojugal. The dorsal surface of the skull was embedded in a mass of ironstone. At my request Mr. Rixon cleaned, with considerable difficulty, the anterior portion of this surface, revealing a series of crushed and displaced fragments. A further area cleaned, in ROMER : LABYRINTHODONT PIIOLIDOG ASTER 143 <= .. ^ ■;: =*H o- - j: o be M 00 aj 1 5 ^ >- Q^ o -^ t:: 3 rS be 9> 't 3 o O CS 5 bD c; r^ ~ 3 s Si. he CS 3 CO 3 ^ •i-^ O ^ r^ O *i X 'qj CS CS (M* 'o S =3 -«" g" OS 3 be w s • •s T) ^ ;h be C3 "o « b 144 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY the left posterior region of the roof, exposed a mass of crushed bone fragments impossible of interpretation, and no attempt was made to clean the rest of the roof, since it is highly improbable that the results would be worth the effort. Anteriorly (Fig. 3), Figure 3. Dorsal view of anterior part of head of type. X V^- Abhrevia- tions: a, angular; d, dentary; I, lacrimal; m, maxilla; n, nasal; pm, pre- maxilla ; sa, surangular. the right premaxilla is apparently present in toto, and a portion of the left is seen as well. Posterior to them are good-sized sculpture plates representing much of the nasals, and to the left of the left nasal much of the left lacrimal and part of the left maxilla are preserved. A fragment posterolateral to the right premaxilla may be an incomplete right lacrimal ; a tooth-bearing strip of maxilla is seen posterior to this. I cannot be sure of the nature of any of the more posterior skull roof fragments. The acid preparation has preserved the sculpture pattern in excel- lent style. There is little evidence of radial arrangement of the ornament, which consists essentially of subcircular pits sur- rounded by well-raised ridges. A considerable amount of bony material, presumably pertain- ing to the palate and braincase, can be seen on the ventral surface between the jaws, but little of it is interpretable. Paralleling the right jaw ramus is a long strip of denticulate bone which is presumably part of the right pterygoid, and opposite this a second dentate area presumably belonging to the left pterygoid. Lower jaw. Nearly the entire external surface of both lower jaws is exposed on the ventral aspect of the cranial slab. The left jaw as preserved measures 186 mm from symphysis to end ROMEU : LABYRIXTIIODONT IMIOLIDOGASTER 145 of artieulai'; one <>aiiis stroiijily tlic impression that anterior and posterior ]iortions have been pulled somewhat apart. The right jaw appears much shorter, measuring 140 mm in length as pre- served, due to the fact that it was so broken post-mortem that the posterior portion has pushed forward under the anterior part. Very probably the actual length in life was on the order of 160 to 170 mm. In the left ramus the distortion is such that the splenial elements, which curved medially toward the ventral surface in life, are flattened into the plane of the angular and dentary, thus giving an impression of greater than true depth. Several fragments include most of the dentary, but nowhere is its alveolar margin present. The left surangular is nearly completely covered by a plate including most of the jugal. Over much of the posterior part of the angular region the surface is eroded. On the dorsal side (not figured) the articular surface is nearly completely visible ; it is, as in many primitive forms, divided into two areas which are at nearly right angles to one another and separated by a rounded ridge. Anteromedially, there is here seen a ridge representing the posterior end of the prearticular and, below^ this, the thickened rounded ventro- medial margin of the angular. On the right side, as noted above, anterior and posterior seg- ments of the broken jaw over-ride one another. The anterior segment includes splenial, postsplenial and part of the dentary. The dentary is so broken that much of its posterior portion is turned over to appear on the upper surface of the slab. Here the middle portion of the tooth row is present, although poorly preserved. Of the posterior segment, the greater part of the angular is seen on the lower aspect. At the back, crushing is such that the articular is seen in posterior view, but preserva- tion is poor. Dorsally is seen a small portion of the angular and the overturned upper portion of the surangular, including its curved upper margin; much of the extent of this bone ap[)ears to have been lost from the margin of the .slab. Our knowledge of the lower jaws of the type is, thus, confined almost entirely to the outer surface. The pattern obviously conforms to that common to many primitive or generalized labyrinthodonts, and shows no diagnostic character of any sort. The Edinhurfjh skull and jaws. Watson (1929) identified as probably belonging to PhoUdogaster a skull in the Royal Scottish Museum (no. 1.10.561) which, from the character of its matrix, appears to come from the Gilmerton ironstone. I see no reason to dissent from this identification. The size and .shape are 146 BULLETIN : MUSEUM OP COMPARATIVE ZOOLOGY appropriate. I have estimated the jaw length in the type as about 160-170 mm; the length of a jaw associated with this Edinburgh skull is 163 mm. As can be seen, the skull is diagnostically anthraeosaurian, as would be expected from the "subanthraco- saurian" nature of the vertebral column. The sculpture of the skull roof is more sharply defined in the type skull, but this is attributable to the acid preparation of the type, whereas the Edinburgh specimen is a split block, in which sculptured ridges are seldom sharply preserved. Figure 4. Dorsal and ventral views of the Edinburgh skull, modified from the restoration by Watson. Abbreviations: ec, ectopterygoid; f, frontal; it, intertemporal; p, parietal; pf, postf rental; pi, palatine; pp, postparietal ; prf, prefrontal ; pt, pterygoid ; st, supratemporal ; t, tabular ; v, vomer. I reproduce (Pig. 4) AVatson's attempted restoration of this skull, with some additions resulting from restudy of the specimen. The skull table is comparable to that of embolomeres, particularly in the fact that, as in that group, the well developed intertemporal extends forward to nearly completely separate postfrontal and postorbital. I believe the tabular-postparietal suture can be made out on the right side in approximately the position indi- cated by Watson. The outer margins of the supratemporal and tabulars curve downward toward the plane of the cheek, but the fact that the right cheek has broken off from the table along the plane of suture between squamosal and table indicates the presence of the zone of weakness here expected in anthra- cosaurians. On the right side of the facial region there are ROMER : LAHYRINTIIODONT PIIOLIDOQASTER 147 indications of part of the .sutural pattern, and 1 have indicated sutures here (with doubt) as broken lines. It seems probable that the lacrimal was excluded from the orbital rim by a pre- frontal-jugal contact. There is a break parallel to the tooth row which Watson has interpreted as the upper border of the maxilla. 1 rather think, however, that this break lies alony the length of the lateral line groove, and that anteriorly the maxilla ex- tended farther dorsally. 1 can make no more of the palatal aspect than the features shown in Watson's reconstruction. The right lower jaw (Fig. ")) is completely preserved as to Figure 5. Inner view of the right iiiaiidiblc of tlie Edinburgli specimen. Anteriorly, the inner surface is absent, so tliat indications of sutures of elements of outer surface are seen. X %■ Abbreviations : a, angular; d, dentary ; pos, postsplenial ; sp, splenial. length, but crushed and partially covered by the skull. It is slender anteriorly, gradually deepening posteriorly. Little can be made out regarding the external surface except that anteriorly, where the inner surface of the jaw is missing, there can be seen indications of sutures between the dentary and a narrow splenial and, more posteriorly, a second splenial element. The inner surface is preserved posteriorly. There is a strong medial proc- ess extending inward below the articular region, apparently corresponding to the region seen in ventral view as part of the crushed right jaw of the type. The inner face of the jaw below and anterior to the articular region is deep ; its upper margin, forming the inner rim of the adductor fossa, bears a low but definite ridge. Farther forward, little can be made out of the inner jaw aspect, but enough is present to show that the large fossae in this region which are characteristic of embolomeres were not present. Lower jaw teeth are not seen, but maxillary teeth are pres- ent. As in the type they are numerous, small and slender ; when completely preserved they are seen to be slightly recurved at their tips, and there is some indication of striation in the basal 148 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY part of the teeth. They are spaced 3.5 to 4 mm apart. It would appear that replacement was actively underway at the time of death, with empty alveoli between most of the teeth present. There is no indication of a developed canine region, but such teeth as are well preserved suggest a region of maximum length of about 10 mm at a point somewhat anterior to the midpoint of the maxilla. Presumably the tooth row (including empty alveoli) included (as Watson's figure suggests) about 30 teeth. DISCUSSION Restoration. Because of the unique nature of this skeleton, I have thought it worth while to attempt a restoration — this despite our inadequate knowledge of certain features (PI. 1, B). Uncertainties regarding skull structure have been noted earlier. The endochondral shoulder girdle and cleithrum are incom- pletely known, but it is reasonable to restore these elements according to the common pattern found in forms removed as far from one another as the embolomere Archeria and the rhachitome Eryops. The manus is missing, the ribs are incompletely known, and few data are available regarding presacral neural arches, but we cannot go far wrong in restoring absent elements in the fash- ion common to most labyrinthodonts. With his short limbs, long trunk and well developed tail, PhoUdogaster was, obviously, primarily a water-dwelling form as, presumably, were all primi- tive labyrinthodonts. Phylogenetic position of PhoUdogaster. In many regards PhoUdogaster is a rather generalized and essentially primitive labyrinthodont. The specimen is well ossified and obviously ma- ture. With a length of about 117 cm — less than four feet — it is a much smaller animal than such well known Carboniferous labyrinthodonts as the large embolomeres of the Pteroplax- Eogyrinus group and such a large loxommid as Megalocephalus. On the other hand, it is not far from the size of the ancient ichthyostegids, and labyrinthodonts Avith proportions similar to those of PhoUdogaster occur at various later levels of the Carbon- iferous. Apart from the vertebral centra, the postcranial skeleton shows few diagnostic features. The broadly triangular clavicular ])lates are presumably primitive in character. Such plates are charac- teristic of embolomeres and seymouriamorphs in later times, but broad clavicular plates are present in some seemingly primitive temnospondyls (as well as advanced forms) and are seen in tlie ROMEK : LABYRINTIIODONT PIIOLIDOGASTER 149 arcliaic ichthyostegids. The iiilorclavicle is luifoi-tiinatoly incom- plete; it was obviously lou^, hut elongation is fouml in sdiiic temnospondyls as well as in anthracosaurs, and one cannot tell whether or not the long stem essentially diagnostic of the later group was present. The ilium shows a long i)osterior process plus, apparently, the small ascending blade foi- sacral rib articu- lation. This structure has long been recoguized as one found in the embolomeres and such further anthraeosaurians or seymouria- morphs as Diplovfrfehron and Discosauriscus. But since we now know that this type of ilium was already developed in iehtliyos- tegids, this feature, again, is not a diagnostic one. Too little is known of limbs in early labyrinthodonts to make profitable an attempt at diagnosis on the basis of limb bones. The vertebral structure, however, is almost unique. As de- scribed above, the intercentra are the prominent elements of the central region — massive structures, although incomplete dor- sally, which form the main supports of the neural arches. The pleurocentra have the form of paired half-rings, surrounding the notochord; they are slender but extend the full depth of the central region. It is entirely reasonable to assume that the vertebral structure of PJwlidogaster represents an initial stage in the development of the anthracosaurian vertebral column, leading to the structures present in embolomeres, seymouriamorphs and typical reptiles. Because of the prominence of the embolomeres in collections of Carboniferous amphibian materials, it was at one time assumed that this type of vertebral structure was a basic one for laby- rinthodonts ; that there had been derived from this, on the one hand, the rhachitomous and stereospondylous types, in which pleurocentra became reduced and the intercentrum became dominant, and, on the other hand, a series in which the ring- shaped embolomerous intercentrum was progressively reduced, thus leading to seymouriamorphs and reptiles. It has, however, become apparent in recent decades that the embolomeres were far from being the sole labyrinthodonts in the Carboniferous. It now .seems clear that, despite their retention of a number of primitive features, the embolomeres are merely a subgroup of one of the two major lines of labyrinthodont evolu- tion— the Anthraco-sauria ; a parallel radiation of rhachitomous forms was also taking place during the Carboniferous. As a result, I proposed in 1947 an alternative scheme of laby- rinthodont evolution — one in which the ancestral type possessed vertebrae which were not embolomerous but proto-rhaehitomous 150 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY (Fig. (')). Typical crossopterygians, from which labyrinthodonts may be reasonably derived, have in many instances large wedge- shaped intercentra and very small paired pleurocentra, situated dorsally near the lower margins of the neural arch. To develop from this the temnospondylous type of vertebra seen in the Rhachitomi requires no change except some modest increase in the size of the pleurocentra to strengthen the column by filling © Q]fe) Embolomeri Seymouriamorpha ® Da ® °'^'° t to Rhachitomi men Schizomeri .^%, 0 Primitive condition Figure 6. Suggested evolutionary series of anthracosaurians, with a typical vertebra representing each stage or group. In each ease the vertebra as a whole is seen from the right side; at the left the pleurocentra (or centrum) shown in end view; at the right, the intereentrum in end view. ROMER : LABYRINTIIODOXT lMIOLirX)GASTER 151 out the gaps in the dorsal part of the central rep^ion where ossi- fication had been lackin<>'. To develoj) an aJithracosanrian type of vertebra would denuiiid a major development of the ))leurocentra. They should expand and coalesce to foi-m a rinpared, CARROLL: DISSOKOIMlll) FAOLrTION 165 and Dr. I)al(|iu'st at Midwestciii ( 'iiivci'sit y, Wichita Kails, Texas, for two specimens of TcrsoiiiiKs which he gave to the Museum of Comparative Zoology. For information coneerninp; the Clear Fork dissoro})lii(ls, and particularly their ai'mor, I am grateful to Dr. DeMar at the University of Chicago, and I wish to thank him foi- permission to summarize his findings. Yale Peabody Museum and tlie American Museum of Natural History have been very helpful in loaning material. I would also like to thaidc Professor Patterson and Dr. Williams for eritical reading of the manuscript. MORPHOLOGY OF TERS0MW8 TeeSOMIUS Case 1910 Tyjjc species. Tersomins texensis Case 1910. New diagnosis: Primitive dissorophid, lacking cranial orna- mentation. Otic notch not closed posteriorly. Frontal bone entering nmrgin of orbit. Each jaw has 45-50 teeth. Internarial bone present. Tersojiiits texensis Case 1910 Figures 1-8 Trrsomin.s ir.rcnsis Case, 1910, p. 180. Type: AMNIT 4719. Small skull with lower jaws. Left nasal region and the very back of the skull are missing and the palate is not exposed. Both orbits show remains of super- ficial eye plates. A second, fragmentary skull accompanies the type. It includes only the back portion of the left side, and apparently it was overlooked by Case in his original and subse- quent (1911) descriptions because of its small size. A tibia and humerus were collected with these skulls, but their size precludes association. Locality: South side of Little Wichita River, Archer County, Texas. Horizon: Belle Plains Formation. Wichita group. Lower Per- mian.- Dicujiiosis: Same as for genus. This is the only species known. 1 .Muscuii) aliliicviatiiins : A.\L\n, AiiiiTicMii Miiscuin of Xaiural Ilistdrv ; BM(XH), r.ritish .Muscuiii (Natural History) : CXILM, Cliicajio Natural History Musi'Uiii : .MCZ, Muspuin of Coiniiara ti\r Zodlog-y : ICMr. riii\ crsii v of Cali- fornia Museum of I'alfoiitolouy : ISN'.AI, Ciiitfd Stati's National Museum: YI'.M, Yale Pealiody Museum. 2 A eorrelatioii chart of rermian and Peiinsylvaniaii sf I'ati.urapliv follows tin- text. Correlation of Texas localities is based un Uonur, liJ.jti. 166 bulletin: museum of comparative zoology Material Studied Since Case's original description, a great deal more material of this species has been discovered. Because there may be some variation from one formation to another, the material from each formation is listed separately. Belle Plains Formation MCZ 3351 and 3352. Two skulls with lower jaws, impregnated with ironstone and slightly distorted. Collected by Dalquest three miles east of Wichita Falls, Texas, E. Morrison survey, abstract no. 186. Putnam Formation, Archer City bone bed MCZ 1912 (Fig. 2). Skull and lower jaws, compressed longi- tudinally but otherwise undistorted, except for crushing of the rear portion of the braincase, occipital region and rear part of the parasphenoid. Collected by N. E. Wright, 1948, one mile southwest of Archer City, Texas ; prepared by S. J. Olsen. The description of the palate and skull roof is based on this specimen. MCZ 1415 (Fig. lA). Skull and lower jaws, complete except for surface of bones in front of orbits, with very little distortion. This skull is the basis for the description of the parasphenoid, occipital region and lower jaw. Collected by R. V. Witter and party, 1936. MCZ 1696. Jaw fragments collected by Witter and party, 1936. MCZ 1694 (Fig. IB), a. Skull behind orbits, probably collected by Witter and party, 1936. Sectioned transversely at y^ milli- meter intervals employing the cellulose acetate peel technique. Basis of descriptions of otic and occipital regions. b. Back of left ramus of lower jaw and fragment of cheek region. Possibly associated with previous specimen. MCZ 3237. Skull in front of orbits with lower jaws in place. Collected with MCZ 1694. Removal of skull roof from this fragment allowed investigation of the dorsal surface of the palate. MCZ 3236. Skull in front of orbits, sectioned transversely at V2 millimeter intervals. Collected with MCZ 1694. Basis of nasal region description. MCZ 3235. Skull in front of orbits with lower jaws. Collected with MCZ 1694. Furnished portions of inner surface of lower jaws not seen in MCZ 1415 or 1694. MCZ 3234. Front of braincase ])etween orbits, sectioned trans- versely at VL' millimeter intervals. Found in either 1939 or CARKOl.L: DlSSOROIMIIl) KVOLUTIOX Ki? 1941. Basis for (Icsci'ipl ion of the anterior I'c^ioii of the l)i'ain- case. Pueblo-Moraii boundary MCZ 11)11 (Fi^'. ID). Nearly complotc skull and lower jaws. Right side of skull turned under palate. Palate hadl}' distorted, left side of skull flattened, back of skull entirely gone. Colleeted by N. E. Wright, 1948. It was found north of the west fork of the Trinity River, section 1834, Texan Emigration and Land Co., Archer County, Texas. c D Fig. 1. Skulls of Tersomius. A, MCZ 1415; B, MCZ 1694; C, AMNH 4719; D, MCZ 1911. X 1. 16S BULLETIX: MFSEUM OF C0MPARATI\T: ZOOLOGY .J^A»7/,< ufiJisid for description: The tollowing desoription is based entirely on the Archer City specimens. BeciUise of the small size and incomplete nature of the tj-pe skull, it cannot be stated eatesrorically that it belongs to the same species as do the other specimens, although there is nothing to differentiate them in the material at hand. In contrast to Case's drawing, the prefrontal and postfrontal do not meet over the orbit. In gen- eral outline, the other Belle Plains specimens, collected by Dalquest. are indistiugnishable from those from Archer City. The matrix has been partially removed from them, but iroustone has destroyed the surface of the bone by infiltration, making detailed investigation impossible. Some features suggest that the geologically oldest skull, MCZ 1911, may differ slightly from the Archer City skulls; its peculiarities will be discussed in the second section. Neither this specimen nor the type is relied upon for this description. Because of the small size and fragile nature of the skulls. it was impossible to clean the inside surface of many of the cranial bones. For this reason it was necessary to section vir- tually the entire skull. Cellulose acetate peels were made from three large fragments of different animals. These peels were stained in a one per cent solution of aniline blue in water. This sttiined the bone a deep blue and the matrix remained its natural color. Unfortunately, not all of the specimens are of the same size or even relative dimensions. For this reason composite recon- structions of the under surface of the skull roof, the braincase. and the upper surface of the palate cannot correspond exactly with the dimensions of the surfaces taken from a whole specimen. Drawings were made from enlarged photographs of the whole specimens and from projections of the serial sections. General Featities of the Skull Evidently the tvpe specimen was an immature animal when it died, since its sutures are open. Although the type and acc-ompanying skull have almost identical dimensions, the latter has closed sutures. Presumably this indicates that these sutures close quite rapidly once the animal has reached a certain age. The estimated length of the type skull is about 60 per cent of that of MCZ 19121 Probably MCZ 1912 and the other Archer City specimens are mature since all fall within about 10 per f-ARKOLL: DFSHOROPHID EVOLUTION UifJ cent of a median sizf. The frafrments art' all of specimens slightly smaller than the complete skulls. Altlioujrh much of the information ref^ardin*^ the skull roof and palate is taken from MCZ 1912 (Fig. 2), a better idea of the relative dimensions is gained from MCZ 1415 fFig. lA;. The roof bones in front of the orbits are mostly destroyed, but the marginal Ijones and the lower jaws are intact, preservinir the outline of the skull. There appears to be very little distortion. The skull is small — only 64 mm from the tip of the snout to the end of the quadrates — and narrow, 47 mm at the widest point just behind the orbits. The highest point on the skull is at the rear of the skull table, 1') rnm above the base of the quadratojugal. The relative dimensions of height, width and length are quite similar to those of Eryops (Sawin, 1941), but the positions of the orbits, otic notch and external nares are not. The orljits are proportionately large, extending laterally to within a milliireter or two of the edge of the skull, and medially to the frontal bones. They are located slightly anterior to the middle of the skull. The external nares are 6 mm in diameter and are located near the margin of the .skull, less than 3 mm from its end. Their separation is equal to that of the orbits, about 10 mm. The septomaxillae cover the posterior portion of the nares. Because of the cur^-ature of the skull, both the orbits and the external nares look out and forward. As in Eryops, the quadrates extend beyond the back of the skull roof. Viewed dor.sally, the skull table occupies most of the width of the skull, but is separated from the jaw suspen- sorium by a deep otic notch, incised 13 mm from the end of the tabular. The side margins of the skull form a continuous arc from the tip of the quadrate to the end of the snout. The skull table behind the orbits is almost flat. In front of the orbits the roof slopes in a convex cur\'e to the tip of the skull. In front of the otic notch the sides of the skull slope down at about a 45' angle. The posterior margin of the skull table is horizontal or slightly depressed above the foramen magnum. The posterior, unsculptured portion of the postparietals and tabulars slopes at about a 45^ angle toward the occipital con- dyles. The lateral posterior surface of the tabulars Ls sculptured and extends posteriori^' beyond the level of the sculptured por- tion of the postparietals. Specimen 1912 has large bony plates extending over the orbital cavity and projecting 6 mm above the skull roof. They are connected to the rear and medial portions of the orbital 170 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY margin and evidently served to protect the eye. Apparently they were composed of one solid piece of bone since there is no consistency between the fracture patterns of the two eye plates. The plates are sculptured in the same manner as the remainder of the cranial bones. Remnants of eye plates were also seen in MCZ 3234, AMNH 4719, and MCZ 1911. The Pennsylvania!! dissorophid Amphibmnus had similar eye plates, both in the Linton species lyelli and the Mazon Creek species grandiceps. The pineal ope!!i!ig' is much further forward in Tersomms than in Eryops. The ratio of its distance from the foramen magnum to the total skull length is 1 :3.5, compared with a 1:9.3 ratio in Eryops (Romer and Edinger, 1942). It is a milli- meter or so in diameter, and is located just behind a line join- ing the posterior margi!is of the orbits. With one exception, the roofing bones are those usually en- countered in an advanced rhachitomous form. The exception is an internarial bone located between the premaxillae and the nasals, i!i the same position as a bone in the ichthyostegids and some loxommids. No ridges, rims or hollows are present on the roof. The i!idividual bones are covered with a uniform fine pitting. This pitting does not extend into the otic !!otch. Presumably the place at w^hich the sculpturing stops !!iarks the position of the tympanic membrane. The occipital surface of the postparietals and tabulars also lacks sculpturing. There are no areas which could be considered as regions of secondary growth in the sense of Bystrow (1935). A ventral view of the skull (Fig. 4A) shows very large interpterygoid vacuities bordered laterally by !!arrow palatal bones. In addition to marginal teeth on the !iiaxillae and pre- maxillae, there are tusk-pairs on the ectopterygoid and palati!!e bones and two tusk-pairs on each vomer. Very fine denticles are present on all the bones except the parasphenoid. These are most conspicuous on the pterygoid. The parasphenoid and rear part of the pterygoids are best seen on MCZ 1415. The posterior plate of the parasphenoid is quite wide and underlies the back of the braincase. Basiptery- goid processes extend laterally behind the articulating rami of the pterygoids, one-fourth of the distance from the back of the skull, to form the basicranial articulation. Tlie cultrifo!-m process continues forward beneath the braincase to reach the vomers, dividing the interptei-ygoid vacuities medially. fWRROI.L : DISSOROPIIin EVOLUTION 171 The internal iiares arc proportionately rather large. Between them, just behind the front of the skull, lies a depression about the same size as an internal naris, termed the internarial pit, formed by the l)endin(l hcnic Ix'twccii tlic nasals and pi-o- maxillao. Tt is locatod at tlic .jiiiicliirc of tli(^ vomers and tho skull roof. Tts jiosition is the same as that of the medial rostral fontanel in Pario.r^ia. the trematopsids, and th(> zati'aehyids. In MCZ .3285, the bone is missinpr, indicatino- the possibility of confusinp: a foramen with the mere loss of the bone. No particu- lar function is su^^ested for such a bone, but it miiiht be noted that the skull roof becomes superflnons where the vomers and premaxillae are in contact with the snrronndino: skull roof units. Th(> j)remaxillae and maxillae meet beneath the hind part of the external nares. Tosether, they bear a uniform assemblajxe of marpinal teeth, each tooth a simple peg, slantinp: sliphtly posteriorly. Room for 34 teeth in the maxilla and 13 in the pre- maxilla corresponds exactly with the number of teeth in the lower jaw. No particular ])attern of tooth succession was noted. The teeth are the same size throu'in is in the plane of the palate and i'orms the medial and posterior marjjins of the ad- ductor fenestra. Dorsally it extends toward the squamosal be- neath the otic notch, fonuinj^ the medial portion of the floor of this sti-ncture. The line of contact between the scjuamosal and ijteryjjoid slojies toward th(> (piadrate at the rear of the skull. Posteriorly, the pterygoid overlaps the quadrate. The palatal ramus extends forward medial to the ectopteryfjoid and palatine bones. On the specimen examined, it does jiot reach the vomers. Such a thin strip i)asses the eetopterygoid and pala- tine that one might suspect that it had originally been wider, although the specimen shows no definite sign of breakage or irregularity. No dorsal groove for a palatine cartilage was seen. The eetopterygoid, bearing one large tooth, forms the fi'ont margin of the adductor fenestra, and extends anteriorly to the palatine. Its lateral margin is covered ventrally by the maxilla. The palatine bears the same relation to the maxilla as does the eetopterygoid, and also carries one large tooth. It has a narrow dorsal ridge on the posterior margin of the internal naris. The vomers form the anterior region of the palate. Posteriorly they border the interpterygoid vacuities, and laterally the in- ternal nares. On the margin of the internal naris each bears a dorsal ridge continuous with that of the palatine and formed in the same manner, by an ineurling of the margin of the bone, best seen in Figure 6 C. The anteromedial portion of the vomers extends toward the skull roof. In front of the nasal sacs, the right and left vomers part to leave a narrow cleft in the palate which is covered ventrally by the premaxillae. Ap- parently this configuration of the vomers serves to support the medial portion of the nasal sacs. The internarial pit certainly is much larger than would be necessary to accommodate the parasymphysial tusks. Posteriorly the vomers rise to meet the parasphenoid and sphenethmoid. The vomers each bear two tusk-pairs. One is located at the anterior margin of the internal naris, in a comparable position to the single pair in Eryops. The other is located posteriorly and medially, halfway to the juncture of the two vomers. Both tusk-pairs are on the rim of the depression between the internal nares. The parasphenoid is divisible into an anterior cultriform process and a posterior plate bearing the basipterygoid articu- lation and underlying the posterior portion of the braincase. The cultriform process extends anteriorly to reach the vomers; 180 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY for most of this distance it underlies the sphenethmoid. It extends across the ventral surface of the vomers approaching the posterior vomerine teeth. Behind the basicranial articula- tion the parasphenoid rises abruptly to a flat platform. Laterally it extends processes that surround the ventral portion of the otic region of the brain. Posteriorly the plate extends to the occipital region, lying just beneath the exoccipitals. Just behind the point of pterygoid articulation, the internal carotid arteries ma Fig. 5. Tersomius texensis. A, Posterior vicnv of skull; B, Dorsal view of palate; dashed line on premaxilla and nasal indicates point at which vomer reaches skull roof. X 1%- CARROLL : DISSOROI'I I ID KVOLT^TION 181 cuter tlic parasphenoid. They are not readily apparent in an intact skull, but are revealed in sectioned material. Tn Eryops these arteries cross the lower surface of the parasphenoid and enter the skull anterior to the pterygoid articulation. The dorsal surface of the parasphenoid will be discussed with the braincase. In addition to carrying the marginal teeth and forming the margin of the skull roof, the maxillae and premaxillae extend ventrally across the margin of the ectopterygoid and palatine bones. The premaxillae do the same beneath the vomers, cover- ing completely the cleft where the vomers approach the skull roof. These are not simply contacts as in Eryops, but an over- lapping, so that removal of the marginal skull bones reveals bones of the palate above them, as if the palate were resting on a moulding. The palate of 2'ersomius differs from that of Eryops in the following features : (1) greater size of interpterygoid vacuities (2) strong contact between parasphenoid and vomers (3) failure of pterygoid to reach vomers (4) overlapping, rather than sutural connection betw^een parasphenoid and pterygoid (5) presence of tw^o vomerine tusk-pairs (6) passage of internal carotids through parasi)hen()i(l Ix'liiiid basicranial articulation (7) presence of internarial pit. The primary pala to quadrate arch: The primary palatoquad- rate arch is composed of the epipterygoid and the (juadrate, re- mains of the palatoquadrate cartilage. The quadrate is a solid bone, roughly tetrahedral in sliape, which articulates with the articular of the lower jaw. The base of the tetrahedron forms the articulating surface and has a concavity parallel Avith the long axis of the jaAV. The medial portion of the articulating surface extends further anteriorly than does the lateral. The dorsal anterior surface is covered by tlie squamosal, quadratojugal and pterj^goid. Only the posterior surface is exposed when the jaws are closed. The apex of the quadrate extends dorsally above the floor of the otic notch. There is an anterodorsal extension of the (juadrate beneath the pterygoid. The epipterygoid, visible only in the sectioned skull, MCZ 1694, is divided into two parts, an ascending process arising just lateral to the basicranial articulation, and a prootic process, 182 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY which is disarticulated from the remainder of the epipterygoid in this specimen. The ascending process is a stout rod of laminar bone articulating with the pterygoid at the juncture of the quadrate ramus and the basipterygoid region. It is 7 mm long and reaches within 1 or 2 mm of the skull roof lateral to the braincase (which is unossified in this area), slanting medially about 20° from the vertical. The rod ends abruptly anteriorly, but slopes slightly on its posterior margin. The base of the ascending process is about 21/2 mm thick. Posteriorly it articu- lates with the basisphenoid and the parasphenoid as well as with the pterygoid. :^x pf f. Fig. 6. Tersomius texensis. Transverse sections of skull ; positions indi- cated in Fig. 2 A. Sections AC from MCZ 3236, D-F from MCZ 3234, F-K from MCZ 1694; stippled areas are restored. X !• CARROLL: DISSOROIMIID FA'OLTTTTON 183 Lateral to the braincase, in the region of the basicranial articu- lation, there are two bony rods -which lie just beneath the skull roof. These do not articulate with any of the otlier l)ones of the skull. The right rod is 3Vi> mm long, and its anterior end lies just posterior to the dorsal extremity of the ascending process of tlie epipterygoid. The left rod is dy? mm long and lies mostly anterior to the ascending process (Fig. 6, sections II and I). Although the bars are of unequal length, it is evident that they are paired structures. From the configuration of the epipterygoid in Dissorophus angusfus (Fig. 13 E) and in several genera discussed by Sushkin (1927), it is evident that these paired structures are the ])rootie processes of the epijiterygoids which have become disarticulated from the remainder of these bones. Judging from D. angustus, the left prootic process is probably nearly complete in this specimen of Tersoniius. The orientation of the bone in the two genera is probably similar, the anterior end articulating with the base of the ascending process, and the remainder of the bone extending dorsally at about a 45° angle from the base of the skull toward the anterior extremity of the otic capsule. Whether it articulated with the otic capsule in Tcrsomius is not known. In Tersomius the prootic process is roughly cylindrical anteriorly, but (piite flat and wide posteriorly. Unlike the ascending process, the prootic process is composed of very porous bone, giving the appear- ance of being hollow at its anterior extremity. There is no real quadrate ramus of the epipterygoid. Because of the deep otic notch, the quadrate ramus of the pterygoid ex- tends far anteriorly and so appears lateral to the ascending process of the epipterygoid for a short distance, effectively sepa- rating the quadrate from the epipterygoid. The great extent of the prootic process of the epipterygoid, and the lack of persistent contact between the epipterygoid and pterygoid differentiate this genus sharply from Enjops. The hraincase (based primarily on sectioned skull MCZ 1694) : In general, the braincase (Fig. 7) of Tersomius is similar to that of other labyrinthodonts in having two main areas of endo- chondral ossification, the anterior sphenethmoid and the pos- terior otico-occipital. Dorsally and ventrally the endochondral bone is covered by dermal ossifications of the skull roof and palate. The lateral walls in the region of the basicranial articu- lation are less ossified than in Eryops, but otherwise most fea- tures are similar to those of that eenus. 184 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY The exoceipitals form the occipital condyles and the side walls of the posterior portion of the braincase. They are fused ventrally, except for the posterior 2 mm. There is no bony basioeeipital, but a g-roove dorsal to the point of fusion of the exoceipitals was evidently occupied by the cartilaginous pre- cursor of this bone. Whether the basioeeipital cartilage con- tinued to the surface of the condyle cannot be determined from the shape of the exoceipitals, but the structure of the atlas suggests that there was no medial area of articulation with the occipital condyle, and hence that this structure was double. The dorsal margin of the foramen magnum is not preserved in the sectioned material, so it is not possible to determine whether the exoceipitals joined one another dorsally, as in Eryops, or whether there was a separate supraoccipital. Dorsally this area is cov- ered by the postparietals which extend lappets on either side of the foramen magnum over the posterior surface of the exoceipitals. The exoccipital extends forward from the condyle approxi- mately 7 mm ventrally, indented al)ove by the basioeeipital trough. Dorsolaterally the exoccipital terminates 214 mm an- terior to the tip of the condyle. Just anterior to the condyle are three or four foramina. There are two distinct ventral foramina, one ahead of the other, just above the basioeeipital groove. The posterior one opens posterodorsally, and the an- terior one posteroventrally. From their position it is evident that they were passages for branches of the Xllth nerve. Dorsal to these openings, there appear openings in each of two successive half -millimeter sections, extending directly laterally. It is not possible to tell whether these represent two separate openings, or the extremities of one large fenestra. It (or they) presumably provided passage for a further branch or branches of the hypoglossal nerve. Anterior and dorsal to these openings is a small foramen, perhaps for a small vein. The otic region is preserved only on the right side of the specimen sectioned. It does not appear to be divided into sepa- rate opisthotic and prootic ossifications. The ventral anterior portion of the otic capsule is either not ossified, or simply miss- ing in this specimen. Since the anterior vertical semicircular canal is partially enclosed in bone, and at least the dorsal margin of the fenestra ovalis is present, the missing portion of the otic ossification cannot be equated with the entire prootie. This re- gion of the braincase is also poorly ossified in other genera of dissorophids (DeMar, unpublished thesis). The otic ossification CARROLL: DISSOROIMIID EVOLT^TIOX 185 is iHoi'c lat(>i'ally dircctrd lliaii in Enjop^, and is not in contact with the exoccipital cxci^pt at its postci-odorsal margin. Laterally and ventralh' there is a cleft between the exoccipital and otic bones that accommodated the vagus nerve, as well as the IXth and Xlth nerves and the jugular vein. Beginning anteriorly about 4I/2 mm in front of the end of the condyles, this passage extends posteriorly to ojieii 1)eliind the otic capsule. This cleft was certainly closed vent rally with cartilage. The posterior wall of the otic capsule extends dorsally and laterally as the paroccipital process to meet the tabular bone. This process forms the ventral margin of the posttemporal fossa, dorsall.y and laterally bordered by the tabular, and medially by the postparietal. This opening continues anteriorly for 4 mm before entering the cranio-quadrate passage lateral to the brain- ease. There is little variation in the dimensions of the post- temporal foramen throughout its length. The fenestra ovalis is located a millimeter or so in front of the rear wall of the otic capsule, beneath the paroccipital process. It is about a millimeter in diameter. Anteriorly it is bordered by bone only dorsally. There is also a foramen in the medial wall of the otic capsule, just anterior to its rear border. Perhaps, as in some lizards (Gaupp, 1900), this opening was occupied by a perilymphatic duct connected with the passage for the vagus nerve. No such opening has been observed in Eryops. The dorsal medial wall of the otic capsule turns medially anterior to the fenestra ovalis and forms the lateral wall of the brain- case. The passage for the Vlllth nerve w^as somewhere anterior to this point, but its exact location cannot be determined. Dor- sally the otic bones almost meet one another in this area. IIow much of the dorsal covering of the Ijraincase was formed by the otic bones cannot be determined since the upper surface of the specimen sectioned is missing in this area. Only the posterior and dorsal portions of the inner surface of the otic capsule are preserved. Dorsal to the fenestra ovalis there is a groove in the roof of the capsule for the posterior vertical semicircular canal. The groove extends anteriorly and iiu'dially. In front of the fenestra ovalis this groove continues, turning somewhat laterally", and becomes enclosed ventrally by bone. This is evidently- the position of the anterior vertical semi- circular canal. Anterior to this point, only that portion of the otic capsule beneath the i)osttemporal foramen is i)reserved. There is no direct evidence for the horizontal semicircular canal. 186 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY A ventral pocket medial to the fenestra ovalis wan evidently occupied by the sacculus and utriculus. The lateral walls of the braincase are unossified between the otic bone and the sphenethmoid. Nerves IV through VII pre- sumably left the brain through this gap. Anterior to the termina- tion of the exoccipital, the base of the braincase is formed by the parasphenoid, presumably covered by a portion of the carti- laginous basioccipital. The posterior margin of the basisphenoid is 3 mm anterior to the end of the exoccipital. The basisphenoid has a groove which corresponds with the basioccipital groove in the exoccipital. This may mark the anterior extension of a persistent notochord. The basisphenoid extends as a stout bar across the parasphenoid, exceeding this bone in width anteriorly. The lateral edges are thickened where it is in contact with the pterygoids. The anterior medial portion of the bone is pierced to a depth of over a milli- meter by paired recesses for the rectus eye muscles, much as in Eryops. Two small foramina lead from the internal carotids into the recesses in the basisphenoid. A third foramen leads into a canal which traverses the basisphenoid between the re- cesses, continuing anteriorly through a small dorsal projection of the parasphenoid, and posteriorly extending into or above the groove for the notochord. It may have contained a vein which carried the blood from the eye muscles, although no passages were seen between the eye muscle recesses and the vessel in the sections examined. The blood probably flowed into the hypophysial vein, although the exact location of this vessel cannot be determined due to lack of ossification in this area. Anterior to the basisphenoid, the parasphenoid forms the bony base of the cerebral cavity. Up to this point the para- sphenoid has always been separated from the cranial cavity by either bone or cartilage and so was not described in detail. Before discussing this area, we should return to the construction of the parasphenoid at the back of the skull. This bone is first encountered beneath the exoccipitals, level with the posterior wall of the otic capsules. It widens rapidly to surround the ventral margins of the otic bones and extends dorsally around their lateral walls. The dorsal margin curves ventrally beneath the fenestra ovalis. Whether there was attachment to the stapes cannot be determined since that bone is not present in any of the specimens examined. Dissorophns multicinctus, from the Clear Fork, has the parasphenoid partially fused to the base of the CARROLL : DISSOROPIIID EVOLITTION 187 stapes. This situation also jji-cvails in Eryops and Edops. AntiM'ior to tho fenesti-a ovalis, the i)arasj)h('iioid is in contact with the portion of tho otic capsule lying beneath the post- temporal foramen. It is difficult to differentiate the two bones in this area. It is j)robabIe that some portions of the bone labeled parasphenoid in Figui"e 5 B are actually part of the otic capsule. The dorsal extension of the parasphenoid ends just posterior to the basicranial articulation. Here the parasphenoid extends bo&nch icf' set ps Fig. 7. Tersomius texctisis. Braincase. A, Median sagittal si't-tion (double hatching indicates restored portions) ; B, Dorsal view of lioii- zontally sectioned braincase, plane of section indicated in A. X -• Com- posite drawings. 188 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY laterally, in contact -with the basipterygoid ramus of the ptery- goid, almost to the quadrate ramus. The parasjohenoid curves ventrally across the area of the basicranial articulation, taper- ing in width anteriorly. The internal carotid arteries enter the parasphenoid just posterior to the articulation. At the point where they enter, they are separated by 6 or 7 mm. They pro- ceed medially forward, immediately beneath the basisphenoid. The canals for left and right internal carotids join one milli- meter beyond the end of the basisphenoid. At their juncture, a small bone is present in the canal, separating it into dorsal and ventral channels ; within a millimeter, however, this bone is gone and the canal opens dorsally. Throughout the area of the basicranial articulation the para- sphenoid is considerably thicker than it is posteriorly. This thickened area continues anteriorly up to the point where the carotid arteries pass out of the bone. The parasphenoid dimin- ishes in width to about 3 mm anterior to the basicranial articula- tion. Just anterior to the basisphenoid, the parasphenoid has a small dorsal extension pierced by the foramen that runs between the recesses for the eye muscles in the basisphenoid. Anterior to this dorsal extension the parasphenoid is oval in cross section for 2 mm, at which point the internal carotids leave dorsally. The pituitary was apparently housed just anterior to the basi- sphenoid, although there is no evidence of a recess for this organ in either the basisphenoid or the parasphenoid. Vessels extend dorsally from the internal carotids in this region; pre- sumably these vessels passed dorsally into a cartilaginous sella turcica. Anterior to this point a trough (a millimeter deep and iy2 mm wide) is formed in the parasphenoid. Anteriorly the walls of the trough are reduced and the parasphenoid continues forward, shaped as a bar, dorsally concave. Within 2 or 3 mm of reaching the vomers the dorsal depression vanishes. In front of the pituitary, the braincase is again walled laterally by bone. Arising from the dorsolateral margins of the parasphenoid and extending anteriorly to the vomers are the paired sphenethmoid bones. In cross section the sphenethmoids form a V-shaped trough. As viewed laterally, each bone is in the shape of a trapezoid, whose top approaches the skull roof. Cartilage probably joined the sphenethmoid to the basisphenoid, with openings for the eye muscles and various cranial nerves. Just ahead of its posterior extremity, the sphenethmoid is pierced by two pairs of foramina. The anterior openings could have accommodated the optic nerve and probably the ophthalmic CARKOI.I. : DISSOROI'ITID EVOLUTION' 189 artery, since the opciiiiifi's are qnitc larii'c. Tlic postorior pair presniiiahly allowed passajje for the oculomotor nerve. Tlie splieiietlnuoids are separated veiitrally by the para- splieiioid for a distance of 6 ram, heyond which they are in contact nntil they eome within 2 or 3 mm of tlie vomers, where they ai-e a'ular. Tlie coronoid lies auter-ior to tlu^ suran'rnsiI. : niSSOHOPlIID KVOLr'PlOX 201 of DisaoropJiKs angustus {vide infra) known from this locality, but the possibility that it beloii<>'s to Tersomius cannot be com- pletely ruled out since that genus, in which the pelvis is un- known, is common in the Archer City bone bed. There are very few features in Williston's descri|)tion of the pelvis of Cacops that do not hold for this specimen as well. The proportions of the tAvo differ slightly, with a larger ])ubis in Cacops. There are also minor differences in configuration. In lateral view, the dorsal margin of the ischium is straight in this girdle, while in Cacops it is slightly concave and there is a more obvious indenture in llic middle of the anterior margin of tlie pul)oischiadie ])late. Probably due to the relatively small size of the pubes, the obturator foramina are placed nearer the anterior margin than in Cacops. The blades of both ilia are broken off just dorsal to the ace- tabula. The inside surface of the ilium, as far dorsally as each is preserved, bears no markings for ligamentous attachment of the sacral rib such as are present in Eryops. The sutures be- tween the bones are difficult to determine. The sutures separating the ilium from the pubis and ischium can be seen laterally, but only the suture between the ilium and the ischium is determinable medially. The ventral surface of the puboischiadic plate shows no division into its components. A single pair of sacral ribs was present within the girdle, but neither rib was in place. From their orientation it is not possible to tell which was right and which was left. The sacral ribs are distinct from those of Cacops, but resemble somewhat those of Eryops. They do not at all resemble those of Dissoroph us multicinctus described by DeMar. The jn-oximal end of each rib is expanded and appears to liave only one surface of articulation with the sacral vertebra. Presumably, as in other dissorophids described, it articulated with both the transverse process of the neural arch and the intercentrum. A short constricted area separates the proximal and distal articulating surfaces. The shaft is curved so that there is about a 45° angle between the surface of the rib articulating with the ilium and the proximal end of the shaft. The distal portion of the i-il> is exininded dorsoventrally about three times the thickness of the shaft. This portion is large enough to cover the entire breadth of the ilium if the size of that bone is comparable to that of other dissoro- phids, so it is unlikely that there were two sacral ribs. Only the medial surface of the distal portion is visible due to the 202 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY fragility of the bones, which made it difficult to clean both sur- faces. The central portion is thickened as a continuation of the shaft. There is an additional thickening on the dorsal (or ventral, depending on which is the right rib) margin. Both the dorsal and ventral margins appear to be finished bone. A fragment of the left femur is attached to the pelvis. The adductor crest is prominent as in all dissorophids. Not enough has been preserved for further comparison. Discussion : From the structure of the armor and the configura- tion of the skull of BroilieUus hrevis, there can be little doubt that this form is ancestral to BroilieUus texensis, although dif- fering sufficiently to be considered a separate species. Two fragmentary skulls described by DeMar, University of Texas nos. 3189-8, both from Thaxton ranch. Clay County, Texas, may belong to this species. According to Romer, this locality is probably in the Admiral Formation, slightly above the Archer City bone bed. The lack of any postcranial material unfortunately prevents definite assignment of these skulls, since it is primarily on the basis of armor that B. texensis, B. hrevis. and Bissorophus angustus are differentiated. DlSSOEOPHUS Cope 1895 DiSSOROPHUS ANGUSTUS^ Sp. n. Figures 12, 13 and 14 Type: MCZ 1695, partial skeleton, including right rear por- tion of skull, vertebral column from atlas to third postsacral with ribs and dermal armor, pelvic and pectoral girdles, and limb fragments. This is the only specimen known. Locality: Archer City bone bed, one mile southwest of Archer City, Archer County, Texas. Horizon: Putnam Formation, Wichita group. Lower Permian. Collector: L. I. Price, 1937. Diaejnosis: Dissorophid possessing a complete set of internal dermal plates above the vertebrae, and an incomplete external set, neither fused to the neural spines, neither exceeding in width the distal extremities of the transverse processes of the fourth vertebra. Otic notch not closed behind. Description: The skull of this animal (Fig. 13) is unfortu- nately quite incomplete. Only the portion to the right of the 1 AngiintUK: I'roiii the Latin mcaiiin}; narrow, in reference to the narrow armor lihites. CARHoi.L : nissonoiMiin evolution 203 midline, hchiiid the orbit, is preserved. What is ])re.sent re- sembles the skull of Broiliclbis brcvis in the ])attern of orna- mentation and the open otie notch. It differs from that species in the much greater de])th of the rear portion of the skull rela- tive to the width of the skull table. The distance between the ext Fig. 12. Dissomphuf! nnpnstus. MCZ 169.1. X 1- front of the otie notch and the back of the orbit ap])ears to be shorter, relative to other cranial dimensions, in this sjieci- men. It is not possible to determine whether the ,iu<>al extends to the margin of the palate since the vertebral column is firmly affixed to the side of the skull. The right rear portion of the palate is also preserved. It is very similar to that of Broilidlns, except that the margin is much lower than the basicranial articu- lation. The pterygoid and ectopterygoid are covered with a 204 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY thick shagreen of teeth. The muscle attachments on the para- sphenoid do not appear qnite as prominent as in Broiliellus. The basicranial articulation is firmly sutural. The skull is fractured so that the openings for the internal carotids are not visible. The stapes is present, but displaced to the rear. It is imperforate as in other Permian dissorophids. The occipital region is better preserved than in other dissoro- phids studied. The major features resemble those of Eryops and Tcrsomins. The occipital condyle is distinctly double. As in Tersomius, the otic bone is located mostly lateral to the con- dyles, rather than hdng mostly dorsal to these structures, as in Eryops. There appears to be a separate ossification, the supra- occipital, medial to the dorsal portion of the exoccipitals. The contact between this bone and either the exoccipital or the otic cannot be seen in the sagittal view. The skull is broken almost at the midline, giving a sagittal view of the braincase. Most of its features resemble those noted in Tersomius. As in Tersomius, a ventral cleft separating the otic and exoccipital bones allows passage for the Xth nerve. Anterior to the otic region there is a large gap in the wall of the braincase, the posterior portion of which results from a failure of the otic capsule to ossify completely. In front of this gap, the epipterygoicl is functionally a portion of the lateral wall of the braincase. This bone is divided into two portions. An anterior rod arises just lateral to the basicranial articulation and ascends to the skull roof. It slants medially at about a 45° angle to approach the midline of the skull roof. Arising from the base of this anterior rod, the posterior portion of the epi- pterygoid slopes posterodorsally and slightly medially to ap- proach the otic bone near the skull roof. Medial to the base of the epipterygoid there is a pronounced depression in the para- sphenoid anterior to the basisphenoid to accommodate the pituitary and the rectus eye muscles. There is no trace of the sphenethmoid. The postcranial skeleton (Figs. 12 and 14) is quite well preserved, but preparation was somewhat complicated by the twisting of the vertebral column into a semicircle. The armor is the most interesting aspect of this species. It is an ideal intermediate between the structure of Broiliellus and that of Dissorophus midticinctus. No armor was preserved above the first 4 vertebrae, but since the 2nd, 3rd and 4th neural arches are broken off, it is probable that the anterior end of the armor was lost in preservation, rather than missing in the CARROLL: DISSOHOIMIII) EVOLUTION 20.") livln ill fi-ont of the at his may have been pai't of a i)r()atlas. There are also modifications in the second vertidira ; the transverse processes are larjz'e and hlunl. and presumably did not bear ribs. No free i)leu]'ocentra are visible between the 2nd and 3rd vertebrae, but there is a separate intercentrum. The anterior zyp-apophyses are only poorly developed but the pos- terior ones are like those of the remainder of the column. The remainino' vertebrae are quite uniform as far as can be judged, except for diminishinji' somewhat in size behind the sacral region. The 3rd through 3()th vertebrae bear strong transverse processes, decreasing only slightly in length posteriorly. Th(\v extend horizontally and obliquely posteriorly as far as tlu^ margin of the dorsal shields. The articulating surface for the ribs is straight and faces slightly ventrally and posteriorly. On the first 21 vertebrae, it is as large as the articulating surface of the ribs. It becomes smaller in the sacral region. The neural arches are consistently 9 mm long from the r)tli to the lOth vertebrae; they decrease gradually to a length of .") mm behind the sacrum. In each of neural spines 15, 16 and 17 there is a vertical groove in the lateral surface for most of its length. The ventral units are concealed by the rib.s or other bones in the anterior region of the column. Where visible, the anterior intercentra do not appear to bear articulating facets for the ribs. In the region of the sacrum the ribs do articulate with the intercentra, but the intercentra are not modified for their attachment. The intercentra are uniformly crescent-shaped throughout the column, as they are in Cacops. The pleurocentra are nowhere clearly visible. The ribs are fairly well preserved. None were found with the first two vertebrae, and from the nature of the transverse processes it seems probable that there were none. This is also the condition noted in Aniphihanixs hjcUi; the condition in other dissorophids is not certain. Ribs are present on the 3rd through 19th vertebrae. These ribs appear single-headed, with little or no articulation with the intercentra. A number are in position, resting directly on the transverse processes, and there is no room for separate capitular heads. The length increases rajudly from the 1st to the 5th rib, after which it decreases gradually for the remainder of the column. The first 4 ribs are of uniform 208 BULLETIN : MUSEUM OP COMPARATIVE ZOOLOGY width, 4 mm, throughout their length. The 5th through 13th ribs have uncinate processes. The 2nd, 3rd and 4th ribs are covered by the scapula so that the presence of uncinate processes cannot be determined. The processes are all located about the same distance from the articulating surface, and so gradually approach the distal extremity of the rib. The processes increase in length from the 5th rib posteriorly, reaching a maximum length of 7 mm in the rib for the 11th vertebra, and decreasing sharply in the 12th. No ribs are preserved on the 20th through 25th vertebrae. Presumably the ribs in this area were similar to those just anterior. The proximal portion of the right rib of the 26th vertebra is present and articulates with both the transverse process and the intercentrum. The sacral ribs, on the 27th vertebra, are also articulated with the intercentrum. They are similar to, although larger than, the sacral ribs in Broiliellus hrcvis. There appears to be less than a 45° angle between the proximal end of the shaft and the surface of articulation with the ilium. This surface is expanded ventrally to about twice the Avidth of the proximal end of the shaft. It is not quite as extensive as the sacral rib in Dissorophus multicinctiis, but the surface of articulation is larger than that in Broiliellus. The ribs on the 28th and 29th vertebrae are similar in size to those on the 26th, and each has a separate area for articulation Avith the intercentrum, and with the neural arch. These ribs are not at all modified to articulate Avith the peh'is. The girdles are fairly well preserved. The right scapulocora- coid is complete although the dorsal portion is covered by the vertebral column. Except for its smaller size, nothing dis- tinguishes the scapulocoracoid from that of Dissorophus mulii- cinctus. The dorsal margin of the left scapula is preserved and shows a truncated anterior margin, similar to that noted in Cacops. A fragm^ent of the right cleithrum lies beneath the vertebral column. This bone is apparently expanded dorsally in a manner similar to that seen in other dissorophids. The stem is not preserved. Both clavicles are preserved. In configuration and extent they are similar to the clavicles of Cacops and Disso- rophus niulticincfus. The dorsal extent of the stem cannot be determined. The interclavicle is present, but its configuration cannot be determined since preparation Avould necessitate de- struction of the clavicles. The right humerus was found in place in the glenoid cavity. The bone was crushed, hoAvever, and presents no details Avorth CAKKOhL: DlSSdKUl'lllI) i;V( )LrTI().\ 209 descrihiii^'. Scx-ci-al toe bones wci'c foiiiid in llic \iciiiil\' of the forolinil). Tlic laf.ucst and most coiiiplctc is (I nun loii'/. 'IMicy are in no partieulai- ordef. The left half of the pelvic ' studied by DeMar. It differs signifieantly from the pelvis associated with BroilicUus hrevis, and also fioin that of Cacops. The pnboisehiadic plate is much more ii])riuhl than in these genera. It is less erect, however, than that of Eri/ops. The ilium is expanded more in an anterior-posterior direction and also more dorsoventrally than in Cacops. its extent is a])])roximately the same as in Dixsorophiis mull Ifiiicl us. 17 16 15 M 13 12 11 10 9 e 7 6 5 Fig. 14. Di.ssoroplius nur/u.stiis. MCZ 1695. Postcrnninl skeleton. A, Lateral view of pectoral girdle ; B, Lateral view of pelvic girdle ; C, Anterior view of pelvic girdle, right side restored from left; D, Vertebral column, ribs and armor. X !/-• The posterior portion of the ischium is missing. A rrushed fragment of the left femur was prescMit in the acetabuluni, Iml no other material from the hind limb was preserved. Discussion: The pattern of armor of this specimen is clearly intermediate between that of BroilicUus and that of Dissofojjhus, as is the number of segments covered. While the posterior shields are generally like those of BroilicUus, the anterior region is Dissorophus-\ike in pattern. The narrowness of the armor reflects the primitive condition observed in B. hrevis. The possession of two flanges rather than a single ventral Hange pi-ojecting from 210 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY the anterior ventral series is nnexpected in an ancestor of Dis- sorophus mulficincfus, but the high deoree of variability in other aspects of dissorophid armor, noted by DeMar, suggests that this is not an important distinction. In other respects this species is an excellent ancestor of Dissorophns multicinctus. An interesting aspect of the armor of this species is its re- semblance to that of Cacops. If the armor were fused to the neural spines, there would be little to differentiate the two. One point of distinction is the composite anterior shield, re- sembling that of Dissorophns multicinctus rather than that of Cacops, in which each vertebra has its own separate pair of shields. Other features of the skeleton, such as the number of presacral vertebrae and sacral ribs, serve to differentiate clearh- these two genera. BrEVIDORSUM^ gen. n. Type species: Brevidorsum profimdum. Diagnosis: Dissorophid possessing ridges around the orbits, but lacking them on the margins of the skull table. Postfrontals and prefrontals not meeting above orbits. Jugal not overlapping quadratojugal or maxilla. Room for 45-55 teeth in each jaw. Otic notch open. Presence of armor not known. Brevidorsum profundum^ sp. n. Figures 15 and 16 Type: MCZ 3250, partial skull and postcranial material in- cluding fragments of both scapulae and cleithra, portions of both humeri, left femur, left tibia and fibula, one or more verte- brae with attached ribs. Locality: North of the west fork of the Trinity River, Texan Emigration and Land Co., Section 1834, Archer County, Texas. Horizon: Near Pueblo-Moran boundary, Wichita group, Lower Permian. Collector: A. S. Romer, 1948. Diagnosis: Same as for genus. Description: Most of the right side of the skull is preserved 'i Breridorsiiw : I'lom the Latin brcris, meaning short, and ilnrsiim (ni'Utor) meaning bacic or ridge, in reference to the limited extent of the ridges on the skull. 2 Profundum: from the Latin nie.ining deep, in reference to the depth of the bacij of the skull. fARKoi.r. : Dissouoriiii) i:\()i,r'i'i()X 211 (Fig. 15), lacking- only the nasal ivi^ion ; only a i'vw fragments of the left side of the skull Uihlc and palate are visible. The general characteristies of the skull are those common to all mTnnnmr c Fig. 15. Brevidorsum profiindum. MCZ 3'J50. A, ])orsal view; B, Lateral view; C, Lateral view restored. X 1- 212 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY Permian dissorophids : a prominent otic notch, open in this wenus, and large orbits which gain contact with the frontals. The skull table is somewhat deeper than in the majority of dis- sorophids, and as a consequence the skull roof descends in a straight line toward the nasal region. The teeth are of the same dimensions as those of most other dissorophids ; if the skull were restored using the pattern of other members of the family, there would be room for approximately 51 marginal teeth in each jaw. There is evidence of a bony eye plate in the right orbit. The skull is probably close to adult size, since it is larger than those of other Wichita dissorophids. The closure of the sutures is complete. The most important characteristic of this skull is the pattern of ornamentation. Ridges surround the orbits and extend onto the nasal region. One ridge lies dorsal to each orbit, arising on the prefrontal anteriorly and passing back across the frontal, postfrontal and onto the postorbital. A second ridge diverges from the first in the prefrontal and extends toward the postero- medial margin of the lacrimal. It terminates at the posterior edge of that bone. A short ridge occurs on the orbital margin of the jugal, but fails to reach the postorbital. In the middle of the postorbital there is a shallow triangular depression, sur- rounded by slight ridges. This pit is in the same position as a similar feature in Cacops. There is also a small pit in the lacrimal just beneath the orbit, and another in the prefrontal. This pat- tern is essentially the same as that observed in DissoropJins and Broiliellus; it differs from these genera in lacking ridges on the rear of the skull table. The only ornamentations in that region are small tuberosities on the postparietals and parietals. One character it shares with Tersomins, in contrast to Broiliellus, is that the jugal does not overlap the maxilla or quadratojugal. The pattern of ornamentation suggests an intermediate condi- tion between the smooth-skulled dissorophids of the Pennsyl- vanian and Tcrsomius, and the typical genera of the Permian, Broiliellus and Dissorophus. The postcranial material is poorly preserved and was freed from the matrix only with great difficulty. The proximal portion of the right humerus is preserved only well enough to identify it as such and note general similarities with other dissorophids. The left femur (Fig. 16 A) is fairly well preserved, lacking only the most proximal portion. The adductor ridge is prominent as is common in dissorophids, but does not extend distally as far as in Cacops. The left tibia (Pig. 16 B) is similar to that of CARKOIJ.: DISSOKOIMIID KVOI.UTION 213 Cacops, but with a nanowiM- slial'l. Only tlic dofsal portion of the left scapula was preserved, it lias a slijiht anterior trunca- tion as was noted in Broilicllus hrcvis and DissoropJius ancjustus. A fra^jnient of the cleithrum is attaclu'd. The rciiiaininn' hones are too fragmentary for meaningful description, or were dam- aged in removal of the bones mentioned. One or two vertebrae are preserved, but unfortunately lack the neui-al spines. The dorsal portion of the block was eroded and so determination of the presence or absence of armor is not possible. Diaciission : The characters of this animal as well as its strati- graphic position suggest that it was transitional between the un- onianiciitcd species of llie Penusylvanian, and liroilicUu^ and A Fig. 16. Brcridorsum profundinn. MCZ 3250. A, Fcimir; Vy, Tibi:i, in posterior, anterior, lateral and medial views. X 1- 214 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY Dissorophus. It seems sufficiently distinct from both of these groups, however, to warrant placing it in a separate genus. The taxonomie status of several additional species is not clear, and should be discussed before considering the evolutionary pattern of the Permian dissorophids. ASPIDOSAUPJJS Broili 1904 ASPIDOSAURUS NOVOMEXICANUS WillistOU 1911 Figure 17 Aapidosaurus novomexicanits Williston, 1911, p. 20. Broiliellus novomexicanus (Williston), Laiigston, 1953, p. 380 (in part). Type: YPM 810, skull and skeleton. This is the only known specimen. Locality: El Cobre Canyon, Rio Arriba County, New Mexico. Horizon: Roughly equivalent to tlie Moran of Texas, AVicbita group. Lower Permian. Revised diagnosis: Dissorophid with a single layer of narrow armor plates, in the process of fusing to the neural spines. Indi- vidual plates not in contact with one another. Some plates longer than others; total number of plates unknown. Open otic notch. Room for 45-55 teeth in each jaw. Twenty-one presacral vertebrae. One sacral ril) ; anterior ril)s with uncinate processes. Description: Although additional specimens have been referred to this species by Case, Williston and Mehl (1913), and by Lang- ston (1953), they clearly belong to a separate genus and will be discussed under Conjunctio. Several changes must be made fi'om the original description of this species, since it was based on an incomi)lete conception of other dissorophids. A complete description is still difficult clue to the fragmentary nature and poor preservation of the specimen. Both the skull roof and the palate are preserved behind the nasal region, together with fragments of both jaws. All the bones of the skull roof lack their original surface and so no sign of typical dissorophid rugosity can be seen nor denied. A depres- sion in the middle part of the skull table is ju'obably only a result of post-mortem distortion, since the skull as a whole is skewed to the right, and the left side is turned under. The pattern of most of the cranial bones is readily determined and differs little from that of Dissorophus, Broiliellus or Tersomius. It is not possible to determine whether the maxilla and quadrato- jugal were overlapped by the jugal since the surface of the CARROLL: DISSOKOIMIII) i:V(MJ"ri().V 215 Fig. 17. AspiJosaurus novomcricanus. YPM 810. A, Dorsal view of skeleton; B, Lateral view of skull; C, Detail of armor attachment, anterior and lateral views. X 1/2. 216 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY latter bone is eroded. The region of the otic notch is well enough preserved to determine with certainty that the notch was not closed posteriorly. The cheek region is relatively deep. Fragments of both lower jaws are preserved, the left showing one tooth, similar in size to those of Dissorophus or BroUidhis. There would be room for 45-55 teeth of this size in each jaw. Only the medial portion of the palate is preserved. The basi- cranial articulation is apparently sutural. The ventral flanges of the parasphenoid, noted in Broiliellus for muscle attachment, are not apparent, but this may be due to faulty preservation. A fragment of the left stapes is preserved, but apparently none of the l)raincase. A large portion of the postcranial skeleton is present, but it is all poorly preserved. Narrow armor plates are preserved dorsal to the 3rd through 9th vertebrae. It cannot be determined whether there were additional plates. None are fused to tlie neural spines, but all appear in the process of fusing. The first and seventh plates are longer than the remainder, but none of the plates are in contact with one another. The entire dorsal surface of each plate is sculptured, so there was apparently no external layer of armor. Each plate is in the shape of a very open, inverted V. There are 21 presacral vertebrae. Their most important fea- ture is the great thickness of the neural spines beneath the armor plates. As was mentioned in the original description, the anterior ribs have marked uncinate processes. The single sacral rib has a wide area for articulation with the ilium. Fragments of the shoulder girdle, one ilium and pieces of the front limbs are present, but the surface is gone from all of the bones. Discussion: According to Langston and to Romer, the El Cobre Canyon locality where this specimen was found is lower than the typical AIjo Formation, i.e., perhaps ecjuivalent to the Moran of Texas. This specimen is hence older than any other armored dissorophid known, with the exception of isolated armor plates from the Moran of Texas. The nearest relationship of this species appears to be with Aspidosaurus chiton from tlie similar- ity of the armor, since both animals have armor of different dimensions in different regions of the column. Although not attached, the armor of A. novomexicanus shows signs of becoming connected, including expansion of the terminal portion of the neural spines. Langston placed this species in the genus IhoUid- Iks on tlie basis of the referred specimens and not the type, wliicli lie was unable to stud}'. CARROLL: niSSOROlMIII) KVOLTTIOX •217 ASIMDOSALRI'S S]). Fimii'c IS ami Plate 1 The earliest dissorophicl aniior known from Texas consists of three neural spines with fused plates from the Moran Forma- tion (MCZ 2740). These were collected by L. I. Price in 1935, one mile northwest of Padgett, northeast part, Wm. Tryndale survey, Young (,'ounty, Texas. They resemble in a general way the armor associated with the tyi)e skull of Aspidosanrus chiton from the Arroyo ( Broil i, 1904). One piece has a longitudinally Fig. 18. AsiiiilosaKni.s sp. MCZ 2740. Tliree neural sjiiiics with fusee ariiior iu dorsal, lateral and anterior (or posterior) views. X 1- and transversely expancU'd dorsal jjortion in the shape ol' an inverted V, with })itting over all hnt the midline of the dorsal surface. Another has only a small expansion of the end of the neural spine; this is sculptured in the mid-portion, but not on the anterior or posterior margins. The spines i-esemble. re- s])eetively, figures 13 and 14 in i)lale VI of Broili. A third, small shield is expanded transversely, bnt not longitudinally, and is either not sculptured, oi- else the surface has w(»atliere(l off. 218 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY Armor of a similar nature has been found in the following additional localities and horizons of the Texas Permian. Putnam Formation : MCZ 1701, Archer City bone bed, Archer County. Admiral Formation : MCZ 2745 and 3162, Briar Creek bone bed. Section 32, Dallas County school land, Archer County. Belle Plains Formation: MCZ 2528, Wm. Mann survey, Section 40, A-271, southwest of Dundee, Archer County; and MCZ 2529, four miles east of Rendham, southwest part of Fayette County school land, Baylor County. In all but the last of these localities, several different shapes of armor are present, but all seem to be within the range of variation of the armor in Aspidosaurus chiton. Other armor, of a much more bizarre nature, is found in considerable quantity at Rattlesnake Canyon in the Admiral Formation (MCZ 1477, Plate 1), and also at Tit IMountain in the Belle Plains (MCZ 2746). The pattern of this armor varies from that observed in Aspidosaurus chiton to that of Platyhy- strix. This type of armor could have evolved from that found in the Moran Formation, but since nothing except the armor is preserved, it cannot even be definitely stated that this animal, or animals, was a dissorophid. CONJUNCTIO' gen- n. Type species: Conjunctio multidens. Diagnosis: Dissorophid with a single layer of narrow armor plates, the anterior plates fused to the neural spines; otic notch not closed posteriorly; 70 or more teeth in each jaw. Pattern of cranial ornamentation similar to that of BroilieUus and Dis- sorophus, ])ut less pronounced. Jugal overlapping quadratojugal and maxilla. Median rostral fontanel. Conjunctio multidens- sp. n. Afipidosaurus novomexicanus, Case, Williston and Mehl, 1913, p. 7. Broiliclliis novotnc.ricanus, Laiigston, 1953, p. 380 (in part). Type: CNHM 673, skull and associated postcranial material including femora, humeri, scapulae, pelvis, section of vertebral column and armor. Illustrated by Case, Williston and Mehl, 1913, figure 7. '^Coiijiniclio: U'inn the Latin coiiiiiiirtio (feminine), nieanin.L,' a jdinini; tojjetlioi'. in rclorcncc to tlic fusion of armor to tlic neural spines. '^Multidens: from the Latin miiltun, meanin,!^ many, and dcitu (masculine) meaning teetli. CARRoiJ. : nissoRDriim evolt'tion 219 Ldcalihi: "West side ol' Piicii-o Kivcf opijositc EI Rito, New Mexico. TInrizn]): A ho Format ion, Lower I'ei'iniaii. CoUrctor: Paul C. Miller. Diafjnosis: Same as for s'enus. Referred specimen: UCMP 4010:1, skull. Localitii: ("amp (jnarry V-2814. one mile southeast of Arroyo de Ag'ua, New Mexico. Horizon: Abo Formation, Lower Permian. Discussion: From re-examination of the type of Aspidosaurus novomexicanus it is evident that the two specimens that iiave been referred to that species belong to a distinct genus and species. In both CNIIM 678 and UCMP 40103 there is room for 70 or more teeth in each jaw, wdiile in the A. novomexicanus type the tooth size of the one or two teeth present indicates that there Avould be room for only 45-55 teeth. Differences in tlie armor are also distinctive. In Aspiclosauriis novomexicanus none of the shields are fused to the expanded neural spines. Only sevoi shields are preserved, none of which is in contact with the others, and the first and seventh are longer than the remainder. In the Chicago Museum specimen, the anterior, although not the pos- terior, shields are fused to the neural spines, and all the shields are in contact with the preceding and succeeding jilates. The total number of shields is not known, but it certainly exceeds seven, and all of the shields are of approximately the same size. The Universit.y of California specimen has no posteranial material. As was pointed out l)y Langston, the general eonfigui-ation of the skulls and particularly the pattern of ornamentation of the specimens that have been referred to Aspidosaurus novo- mexicanus are very similar to those of BroilicUus. There are, however, other features of the skull and particularly of the armor which separate the two groups. Three features differentiate the California and Chicago skulls from BroilicUus hrevis and B. texe7isis. The former have a great many more teeth, the pattern of ridges is more subdued, and there is a median rostral fontanel. The width of the armor is on the order of that obsei-ved in Broiliellus hrevis. The armor differs, however, not only in the fusion of the anterior plates, but also in the shape of the indi- vidual shields ^ relatively flat in B. hrevis, and in the shape of an inverted V in these specimens. Both specimens of Conjunctio multidens were collected from 220 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY the Abo Formation near Arroyo de Agua. According to Eomer, the Abo is roughly equivalent to the Putnam Formation, perhaps including the upper portion of the Moran and the lower Admiral. Their stratigraphic position as well as their morphology sug- gests derivation from B. hrcvis or a closely related predecessor. They clearly represent a different line of development from that expressed by BroilieUus hrevis and B. texensis, and so should be placed in a separate genus. CoNJUNCTio sp. Figure 19 A third specimen (MCZ 2369) obviously referable to Con- jnnctio has been found in the Admiral Formation of Texas. It was collected by Dr. Romer in 1950 from the Halsell Hill locality, Section 19, Halsell subdivision, Clay County, Texas. Like the New Mexico specimens, it has a large number of teeth, a median rostral fontanel and a similar pattern of armor. No specitic features separate it from the other members of the genus, except its place of discovery. This, however, is itself quite significant since the Texas and New Mexico land areas were separated during the Permian by a long arm of the sea, and only one vertebrate species, Zatrachys serratus, has been reported in both areas (Langston, 1953). For this reason I hesitate to place this speci- men in the same species as the New Mexico specimens, despite their morphological similarities. All three specimens are of about the same geologic age. The specimen includes the skull and fragments of both lower jaws, about 14 vertebrae with ribs and armor, portions of the shoulder girdle and front limbs. Tlie skull roof is almost com- plete, lacking only the right front margin, the back of the skull table and the rear portion of the upper jaws on both sides. The skull has been greatly flattened, particularly in the antorbital region, distorting somewhat the outline of the skull. If restored to its original shape it would resemble closely the skull descril)ed by Langston which I refer to Conjunctio multidens. The i)or- tion of the skull posterior to the orbits is relatively short, as in other dissorophids from the lower ]^art of the Wichita. The right tabular is intact and there is no bar closing the otic notch. The pattern of ornamentation is the same as in other members of this genus. The jugal overlaps the quadratojugal and maxilhi as in BroilieUus hrevis. A scrap of bone is present in the left orbit, presumabl\- representing tlie remnant of a supi'aorbital rAKH()i,F>: nissoKoiMMi) i:\()i,r'i'iON 221 plate. Tliere is a sn^-ocstion of sclci-otic plates in llie same orbit. Since selerotie plates are present in the I'ennsylvanian dissoro- pliids, tliey presumably existed in all of the Permian members of the family as well. Most of the suture lines ai-e visible, or can be readily restored by comparison of the two sides of tlie skull. Tbe confi«;uration of the individual bones diff(M-s from that of Broilicllns or 7Vr- somius only in the "Teater length of the nasals as compared vith the frontals. This, of course, is acceutnatcd by the fiattening of the forepai't of the skull. The median rosti-al fontanel is in the same position as is the internai'ial bone in Tcrsoniiiis, and of about the same size. The left lower jaw is fortunately displaced inward, allowing all of ihe teeth in the upper jaw to be visible. In spite of a short gap in th(> tooth vow in the maxilla, there are 48 teeth, with room for 16 more, not counting the ga]^ which could have accommodated about 6. The premaxilla has 10 teeth, with room for 6 more. The teeth are considerably largei- in the premaxilla and anterior portion of the maxilla than they ai'e in the posterior region of the upper jaw. All of them ai'c bi-oken off, but would probably havc^ been a millimeter or two in length. The jaw fragments are too incomplete to describe. Two small blocks of matrix containing a number of vertebi-ae, ribs and armor were found together with the skull. The bones are broken and jumbled in a very hard matrix, so few details are visible. The atlas and axis are not present and other anterior vertebrae may also be missing. The neural spines of the first two anterior vertebrae preserved are truncated and the armor is lost. The 3rd through 9th vertebrae have fused armor plates. In the second block of matrix, probably contiguous with the first, the first vertebra is truncated dorsally while the second has a fused armor plate. If it is assumed that only the atlas and axis are missing from the anterior block, the fii'st 13 verte- brae have fused armor plates. The neural spine of the 14th A'ertebra is complete and lacks fused armor. A free armor plate lies close to this vertebra, but could equally well have come from further on down the column. The 15th and 16th vertebrae have broken neural spines ; no others are present in the block. Only the single free plate was found. None of the fused plates are complete; all have been broken on the margins. Each had been about 5 mm long, and perhaps 10 mm wide. The sides meet at an angle of about 135°. On the dorsal surface, immediately above the neural spine, the armor is not sculptured. The sides, hoAvever, are deeply pitted. 222 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY mrf Fig. 19. Conjunctio sp. MCZ 2369. A, Dorsal view of skull; B, Voiitial view of skull; C, Right and left views of blocks containing postcraiiial material; D, Detail of free armor plate in dorsal and anterior views. X 3/4. CARROLL: DISSOROI'lIII) KVOU'TIOX 223 The siiitiic piece of free aniioi- is well pi-eserved. A Permian or late in the Pennsylvanian. If A. novomexicanus is accepted as an early member of this group, it is probable tliat, CARROLL: DISSOROPIIID EVOLUTION' 227 as will] the otlicr (liss()r()|)li!(]s. the ai'iiior fii-st dcvcloppd as separate dci'inal ossifications situated dorsal to the neural spines, secondarily beeoniinu' fused. Tf this were the case, there may have heen a connnon ancestor of hotli the Aspidosaurus u-roiip and the reinaindei- of the dissoi-ophids that had a small numl)er of narrow, unfused arnioi- jilates above the anterioi- i'e<:ion of the vertebral column. Tt is at least possible that Brcvidorsum }>ro- fuvfhtm or a closely related predecessor had these characteristics. Tn this discussion of phylogeny there has been no attem])t to separate the evolutionary line that occurred in Texas from that developed in New Mexico. Such a separation is simply not pos- sible with the limited number of j^enera known from New Mexico, and the limited time span of the New ]\Iexico beds. PENNSYLVANIAN DISSOROPHIDS Since dissorophid remains are present in the very lowest beds of the Texas Permian, it is natural to look for their antecedents in the Pennsylvanian. Dissorophids have been described from Mazon Creek (Greoory, 1950), and members of this family have been mentioned from the fauna of Nyrany. Bohemia, and from the Paris shale of Kansas (Romer, 1947). The best preserved Pennsylvanian dissorophids, however, are from Linton, Ohio. Several specimens pertainiufy to members of this family have been discovered by Dr. Baird during his extensive preparation of that fauna. Because of the investing matrix, the early descrip- tions of this materia] were rather incomplete and led to the erection of a number of genera. It now appears that all of the dissorophid material from Linton belongs to a single genus and species. This species resembles Amphihamu^ f/randiccps in many features, but is sufficiently ditferent to be placed in a separate species as Amphihamus lyelli. Amphibamus LYELLI (Wymau) Figures 21-25; Plate 2 Raniceps Iijrlli Wyman, 1858, p. 168. Pelion lyelli (Wyman), Cope, 1868, p. 221. Tuditanus mordax Cope, 1874, p. 274. Diceratosaurus punctolincatus, Moodie (not Cope, 1875), 1909, p. 25. Diccratosaurm punelolinratus, Moodie (not Cope, 1875), 1916, p. 118. Diceratosaurus brevirostris, Eomer (not Cope, 1874), 1930, p. 91. Platyrhinops mordax (Cope), Steen, 1931, p. 865. 228 BULLETIN : MUSEUM OP COMPARATIVE ZOOLOGY Type: AMNH 6841, skull and complete skeleton. Referred specimens: AMNH 2566, cranial fragments; BM (NH) K.2670, skull; USNM 4461, partial skeleton; MCZ 1277, lower jaws and palate. Horizon and locality: Upper Allegheny. All from Linton, Ohio. Revised diagnosis: Primitive dissorophid. No cranial orna- mentation, pre- and postfrontals meetino; above orbit. Seventy to eighty teeth in each jaw. No armor. Descripiion: The skull roof of the type specimen of Amphi- hamus lyelli (Fig. 21 A) is nearly complete, although slightly disarticulated at the margins. It is flattened in the manner of all Linton material, with the skull roof forced almost into the plane of the palate. The only portion of the skull that is missing is that anterior to the external nares. The occipital region ex- tends horizontally behind the skull table, but shows few details. TABLE 3 Cranial Dimensions of Amijliihamus Length of cranium to extremity of quadrate Length of cranium along midline Greatest width of cranium between quadratojugals Least width between orbits Transverse diameter of orbits Longitudinal diameter of orbits Distance from center of orbit to quadrate Distance from center of orbit to front of skull Distance of pineal from back of skull roof Back of orbit to front of otic notch 1 Measurements taken from drawing of specimen. Dimensions of specimens are to the nearest millimeter. The displacement of the marginal bones, together with the gen- eral compression, renders exact determination of dimensions difficult. It is about half the size, in any linear dimension, of Am IJliibnmus hjcUi Amphibamus calliprcixx T.vpe AMNH I5M(NH) 6841 R.2670 1 ;\icz 1277 nM(NH)i K.2817 31 — 64 — 26 40 32 57 56 51 8 10 9 19 — 14 14 — — 17 14 6 ~ " ~ 11 — 9 4 9 CARROLL: DISSOROPIIID KVOH'TIOX 229 MCZ 1277 and BM(NH) R.2670. The closure of the sutures and the high degree of ossification of tlie skeleton, however, indicate tliat this specimen was an essentially mature individual. The general skull shape closely resembles that of Tersomius -. large, closely-set orbits, deep otic notches and a roughly tri- angular outline. There can be no question of the supratemporal- tabular suture as there is in A. grandiccps. The tabulars are small bones extending beyond the posterior margin of the skull table, slightly disarticulated from the supratemporals. The post- parietals are relatively larger than those in A. (jrandiceps but, pm ppc Fig. 21. Amphibamus hjelli. A, Skull roof, AMNH 6841; B, Palate, AMNH 6841; C, Palate, MCZ 1277. X 1- 230 BULLETIN : MUSEUM OP COMPARATIVE ZOOLOGY like the tabulars, smaller than the corresponding units in Ter- somius. The area of the skull table behind the orbits is shorter, relative to the total length of the skull, than that in Permian genera, but perhaps slightly longer than in A. fjrandiceps. The bones ventral and anterior to the otic notch are displaced and partially obscured so that little can be said of them. The bones of the orbital margin differ from those of Permian dissoro- phids in that the pre- and postfrontals are in contact above the eye as they are in A. grandicops. The jugals and lacrimals may make slight contact beneath the orbit, but this is not certain. The medial bones of the skull roof differ little from those of other dissorophids except that the frontals do not enter the orbital margins. The pineal opening differs from that of the other species of dissorophids only in the better preservation which shows the presence of a circular ridge surrounding the opening. The anterior ends of the nasal bones are presumably lost along with the posterior margins of the premaxillae ; at least, the adjacent margins of these bones cannot be made to match. Only the general position of the external nares can be determined. There is no sign of the septomaxillae. The front margins of the premaxillae can be determined by the position of the lower jaws. It is not possible to determine the presence or absence of an internarial bone. The maxillae are both turned under the edge of the skull so that only their dorsal margins can be seen, together with portions visible through the orbits. Teeth are visil)le in side view in front of the right orbit ; they will be described together with the palate. Numerous pieces of sculptured bone are visible in Ijoth orbits. They are evidently remains of palpebral cups such as are present in Tersomius. Six sclerotic plates are visible beneath the left orbit, and two beneath the right in MCZ 1277. Presumably the animal had a ring of sclerotic plates similar to that described by Watson in Amphihamus grandiccps. Like the type, the British Museum skull BM(NH) R.2670 has been subjected to crushing, which has disturbed the margins of the skull and forced the side walls into the same plane as the skull table. Restoration of these features produces a con- figuration very similar to that of the type, except for the greater distance between the orbits in BM(NII) R.2670. It is easy to interpret this difference as resulting from the larger size of this specimen. Fragments of the palpebral cups were noted by Steeii ill the same position as in the type. CARROLL: DISSOROPIIID KVOLT-TrO.V 231 The jialalo (Fij>s. 21 B and (' ) is similar in liciici-al 1o that of Permian dissorophids. Detailed structure is difficult to deter- mine, however, since all of the specimens studied have a tliick layer of denticulate "skin" covering most of the surface of the palate. The posterior repion of the pterygoids can be seen in tlie Britisli Museum specimen, with the exception of the basi- pterygoid articulation. This region is unfortunately obscure in the other specimens as well. The anterior portion of the ptery- goid is also missing or obscure in all of the specimens. Enough of the vomer is visible in AMNII 2566, howevei-, to indicate that the pterygoid did not reach that bone. Both ectopterygoids, each bearing one tooth, are present in BM(NH) R.2670, although somewhat disarticulated from the remainder of the palate. The relative position of the ectopterygoid can be judged in MCZ 1277 since the ectopterygoid tooth has penetrated the left lower jaw. The palatine bone and accompanying tooth can be seen only in AMNH 2566. Unfortunately, even in this specimen the posterior portion of this bone is missing and its relationship to the ptery- goid can only be estimated. The palatine tooth is more laterally placed than its counterpart in Permian dissorophids. The vomers are not completely visible in any single fossil, but from the several specimens their configuration can be deter- mined. It is apparent that Steen's reconstruction of these bones places them too far posteriorly. In her specimen, the bones have either become disarticulated from the anterior margin of the skull, or the covering of denticulate "skin" has spread over the posterior margin making it appear that the bones extend into the interpterygoid vacuities. The relationship of the vomers can be seen in the type skull and in AMXIl 2566. One pair of prominent vomerine teeth is situated just medial to the anterior margin of the internal nares, but there is no sign of the second pair noted in Tersomiiis. The anterior region of the vomers is covered by denticulate "skin" in all specimens; thus the pres- ence or absence of an internarial pit cannot be determined definitely. An internarial pit has not been described in A. (jrandiceps. The configuration of the internal nares was deter- mined from AMNH 2566. Their position is similar to that in Tersomius, although they are somewhat narrower. What were described by Steen as internal nares must have been only a rent in the palatal "skin" since their position in her reconstruction is much closer to the margin of the vomers than in any other dissorophid. 232 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY The parasphenoid is most readily observed in the British Museum specimen; unfortunately, it has separated from the pterygoids, and the adjacent margins of both bones are missing. Probably the relationship of the bones is similar to that observed in Tcrsomius, in which the parasphenoid overlaps the posterior margin of the basipterygoid process of the pterygoid, and the pterygoid and basisphenoid are in contact but have not com- pletely fused. The position of the internal carotids is the same ^^?fifet2iM^vtm#iM^^^^ Fig. 22. Amphihamus lyeUi. A, Eestoration of palate; B, Eestoration of lower jaw, based primarily on ?*ICZ 1277, ventral view; C, Lateral view; D, Medial view. X 1- CARROLL: DISSOROIMIID EVOLT'TION 238 as in Tc7\^o))iius. The doi'sal I'xtciisions of llic i)ai'as])li('ii()i(l plate lateral to the braiiicase, seen in Permian dissoropliids, are not preserved in any of these specimens. The enltriform process is best viewed on tlie type. Its anterior extremity is expanded laterally where it is in contact with the vomei's. I\rar<;-inal teeth are present in MCZ 1277, in th(^ tyj)e, and in A^IXII 2566. Althongh the entire conii)h»ment is not ])resent in any of these specimens, the number and density in all parts of the upper jaw can be determined. Tlic numhci- of teeth is approximately the same in all of the specimens i-e^ardless of the size of the skull. There is room for 21 in each premaxilla and 55 in each maxilla, compared with 13 and 34 respectively in Ter- soniius. They are the same size throughout the jaw ; in the larger specimens they reach a length of about 2 mm. In the reconstruc- tion (Fig. 22 A), the tooth replacement pattern in the right maxilla is based on MCZ 1277 ; the position of teeth and pits in the rest of the skull is arbitrary. The quadrate is slightly visible in MCZ 1277, but the recon- struction is based primarily on other dissoropliids. Only in the type specimen is the sphenethmoid visible. Al- though incomplete, it apparently resembled that bone in other dissorophids. Except for the occipital region in the type, the posterior portion of the brainease is not visible in any of the specimens. A layer of denticulate "skin" covered almost the entire palate in the living animal. Gaps were present for the reception of the palatine teeth, and in the region of the internal nares and adductor fenestrae, but most or all of the interpterygoid vacui- ties were covered. The denticles, particularly large in the region of the pterygoids, must have been of use in holding prey. It seems doubtful that such a thick layer of denticulate "skin" covered the palate in Permian dissorophids, which all have denticles growing from the bones themselves. It may, however, have covered the interpterygoid vacuities in these genera. The reconstruction of the palate (Fig. 22 A) is probably accurate in the representation of individual units; however, one entire specimen might have somewhat different relative dimensions, since specimens of several sizes were used in making this reconstruction. The lower jaws are restored primarily on the basis of MCZ 1277. The general configuration of the jaws can only be ap- proximated since they were all somewhat crushed into the skull roof on the specimens studied. The only point of ditference 234 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY from the customary rhachitomous pattern is the apparent unity of the angular and surangular. Not only is there no suture separating them, but even in the pattern of dermal sculpture they appear as one. This is probably a result of the age of the specimen since it is the largest of all known Pennsylvanian dissorophids. This suture is also difficult to find in some speci- mens of Tcrsomius. The features of the skull of A. lyelli generally resemble those of Tersomius and the other Permian dissorophids, except for the contact of the prefrontal and postfrontal above the orbit, and the greater density of marginal teeth (exceeded only by Co7ijunctio). The region of the skull roof posterior to the orbits is shorter relative to the anterior region of the skull than in advanced dissorophids, but similar to that of Tersomius and Amphihamiis grandiceps. The type specimen includes an almost complete skeleton, lacking only the tail and some of the fingers and toes. The specimen is preserved so that most of the right side is visible, with some features, however, present in a cast of the opposite side. Supplementary information is provided by USNM 4461 (Fig. 24). This specimen unfortunately lacks the anterior end of the skeleton and the skull. Judging from the relative size of the skull and postcranial material of the type, this specimen must have had a skull about the size of MCZ 1277 or BM(NH) R.2670. There are 25 presacral vertebrae in the type specimen. The exact number (if there is a fixed number) is in dispute in A. grandiceps. Watson (1940) and Gregory (1950) agree that CNHM 2000 has 18; Gregory notes 21 in the type of Mazon- erpeton, which Moodie (1916) says has 27. The first two verte- brae are modified and might be called cervicals. The first lacks transverse processes and ribs, is much narrower than its fellows, and has special articulations with the occipital condyles and with the second vertebra. The exact nature of either of these articulations is uncertain. A single neural spine is visible ; whether a second was present as in Dissorophus (Williston, 1910) cannot be determined. The spine is narrow, and appears slightly shorter than those of the remainder of the anterior vertebrae. The atlas does not overlap the second cervical to the extent seen in Dissorophus. The neural arch of the atlas is fused to the intercentrum. No separate pleurocentra are visible, and they too may be fused to the arch. No proatlas was seen. CARROT, L : DISSOKOIMl II) KVOIJ'TIOX 235 The secoiul vortehi-a luis a slioi-f neural arcli, small transverse proeess(>s, and no ril)s. It articulates with the atlas by an ill- defined anterior extension above th(> neural canal. Its posterior zyp-apophyses are like those of the rest of the column. Between the second and third vertebrae there is a free iiitcrcentrum, but uo plenrocentra are visible. The ;?rd vertebra is similar to numbers 5 through 25 ; the 4th, however, is modified in having a shorter neural spine, eontribut- ing as in Eryops to greater ease in lifting the head. Vertebrae numbers 3, and 5 through 25, ai-e (|uite uniform and display the normal rhachitomous pattern. The neural spines are all short and unornamented. There is one sacral vertebra which bears a large sacral rib, as in Eryops and Dissorophus, but unlike the condition in Cacops. Five postsacral vertebrae are visible but are so badly crushed that just enough remains to show a general resemblance to the dorsals. The position and general configuration of the intereentra and plenrocentra are visible in numerous vertebrae, but no thorough description is possible since they are always somewhat obscured by the remainder of the vertebrae, the ribs and matrix. Ribs are present on all the vertebrae behind the cervicals. There may have been a small rib on the second vertebra, which bears a reduced transverse process, but none is visible. Dissorn- phus angnstus has no rib in this position; the condition in .1. (jrandiceps cannot be ascertained. The first three ribs are the longest (5 mm) and have widely expanded, overlapping ends. The fourth and fifth ribs are transitional, while the rest of the column bears ribs without distal expansions. Behind the shoulder region the ribs become shorter, having a length of only 3 mm just anterior to the sacrum. The ribs of the first two postsacral vertebrae are about this same length. The next two ribs are longer and the last visible one is very short. None was seen on the 32nd vertebra, but exact determination was difficult due to its crushed condition. The posterior ribs are much better preserved in HSNM 4461 than they are in the type. Dorsally, presacral ribs 12 through 18 appear as straight rods, terminating in the tubereulum. Ventrally, the ])roximal half of the rod has a slender flange which terminates at the capitulum. The tubereulum and capitulum extend dorsally and ventralh' from the body of the rib but aj)parently remain connected. Near the sacrum the ribs do not bear this ventral flange so that the two heads together form a greatly expanded portion at the immediatelj^ proximal end. The two heads are 236 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY X CARROLL: DISSOROPIIID EVOLUTION 237 partially separated hy a fjroove on the rear surfaee of the rib. Tlie anterior surface is not visible. The anterior ribs articulate -with both tlu» transvei-se process and the intercentnini, althoufrh the latter element does not have a particular area for its attachment as it does in Cacops. The ribs in the mid-portion of the column probably did not articulate with the intercentrum. Both sacral ribs are preserved in the type ; the left is visible from the medial surface affixed to the left ilium. The right is seen in lateral view, having ])artially separated from the right ilium. Each sacral rib includes a transverse l)ar articulating with a large transverse process of the sacral vertebra. This bar bends sharply caudad after contact is made with the ilium. It is not possible to determine the exact extent of the blade of the rib. The right appears similar to that of Broiliellus hrevis, while the left appears more extensive, similar to that of Bis- sorophns multicinctiis. Neither of the adjacent ribs is at all involved in the sacrum. The pectoral girdle is essentially complete, although somewhat disarticulated. Its structure conforms to the general rhachi- tomous pattern. The scapulocoracoid plate is complete except for the glenoid region, which is obscured by the humerus. It is proportionately wider (or shorter) than that of Eryops. The scapulocoracoid plate compares very well with that of Amphihamus grandiceps. The cleithrum, as in that species, is restricted to the upper margin of the front of the scapula ; there is little dorsal expansion, such as is visible in Eryops, and the stem is quite short. The stem of the clavicle extends further dorsally than it does in Eryops. The ornamented ventral extension of the clavicle articulates with the interclavicle. The latter bone can be seen only in dorsal view, partially concealed beneath the left coracoid. Its exact nature cannot be determined, but apparently it was similar to the interclavicle of Ampliihanius grandiceps. The left scapulocoracoid can be seen from the in- side, but it is covered by the vertebral column so that no details are visible. The position of the pectoral girdle along the verte- bral column shown in Figure 25 is only approximate, based on the condition in Eryops and Cacops. The humerus is longer, relative to the length of the vertebral column, than in either Eryops or A. grandiceps, having a con- siderable shaft between ends expanded at right angles to each other. The ectepicondyle and entepicondyle are visible on either side of the ulnar articulation. The position of the limbs prevents 238 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY checking the presence of the pectoral process which was noted in A. grandicrps by Gregory. The limbs are turned so that the proximal expansion can only be seen on edge, hence its extent cannot be stated. The ulna and radius are considerably shorter than the humerus. The ulna is best preserved on the right side ; it is in place and the olecranon extends around the end of the humerus as a triangular process. The radius is slightly shorter than the ulna and expanded distally. There are no ossifications in the region of the carpals. All four digits of the left manus are well preserved, lacking only the distal phalanx of the lateral digit. The metacarpals are about one-half the length of the radius ; the medial is the shortest and the next to medial, the longest. The proximal phalanges are about the length of the metacarpals ; the distal ones are half that size and bluntly pointed. From the propor- tions of the remainder of the hand, one and only one phalanx can be added to the last digit. The phalangeal count is the same as in A. grandiceps : 2, 2, 3, 3. As in A. grandiceps, the third digit is the longest — somewhat longer than the humerus. The length of the digits and their compact form in the fossil suggests that webbing may have been present. The dorsal portion of the pelvic girdle is clearly exposed. The lateral surface of the right half is visible, while the left shows its medial surface, partially covered by the right. As well as can be judged, each half is completely ossified, with no sign of sutures separating the individual bones. The most striking feature of the pelvis is the height of the ilium — quite similar to that of Eryops. On the lower portion of the posterior margin there is an indentation, below which is the ischium. Above this notch is a rugosity for a large muscle insertion. A small eleva- tion is visible in this area in Eryops, and a large rugosity in Dissorophus. The ischium extends a considerable distance posteriorly. The puboischiadic plate is mostly missing and with it the bottom of the acetabulum and the ischiadic prominence. A well ossified pubis extends anteriorly. The anterior margin of the acetabulum is similar to that of Eryops. Dorsally there is a large central recess, the supra-acetabular notch. In general, the pelvis resembles that of Eryops more than it does the later dissorophids. The pelvis of USNM 4461 is essentially the same shape as that of the type, again lacking the bottom of the puboischiadic CARROLL: DISSOROPHID EVOLUTION' 239 plato. p]iiongh of this is present, liowever, to indicate tlie pres- ence of a small ischiadic prominence almost directly beneath the supra-acetabular prominence. The latter has the same posi- tion and configuration as it does in the type. The ilium differs from that of the type in being relatively shortei-. 'riie ischium is apparently broken at the rear. Fig. 24. Amphibamvs hjelli. USNM 4461. X 1. Neither of the femora in the type is well preserved and both are turned at angles, obscuring the features most suitable for comparison with other dissorophids. Their most notable charac- teristic is their great length and lack of girth. The left femur is exposed in dorsal view, and both ends are crushed, obscuring any possible definitive features. From the rear an adductor crest is Adsible, but not sufficiently for description. The right femur can be seen in ventral view, showing a narrow adductor crest on the anterior, proximal margin. Both the proximal and distal ends are expanded, less so than in the Permian dis- sorophids, but with the same general configuration. The femur of USNM 4461 is preserved in rear view, allowing observation of the adductor crest not possible in the type. The crest is restricted to the proximal half of the bone. It expands from the middle to within a millimeter or so of the proximal end, at which point it descends toward the articular surface. The dorsal surface of the femur is more concave, as viewed laterally, than that of any later dissorophids. Tiiere is an 240 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY obvious surface for articulation with the fibula. The dorsal depression and the shape of the adductor crest are very similar to those observed in Arkanserpeton. The fibula of the type is thinner and just slio-htly longer than the tibia. In Eryops the tibia is markedly longer, in Cacops slightly longer. The proximal expansions of the bones are about equal, while the distal expansion of the tibia is slightly larger than that of the fibula. The tarsals consist of five patches of cartilage. The foot can be almost completely reconstructed from AMNH 6841. Of the five digits, only the distal phalanges of the lateral two are missing. The metatarsals are about one-half the length of the tibia ; the medial one is the shortest ; the remainder are all of approximately the same length. The proximal phalanges are all about the length of their metatarsals. The distal phalanges, like those of the hand, are half the length of the proximals and bluntly pointed. The second and third digits are the longest, both exceeding the length of the femur. As in the hand, webbing seems probable. The phalangeal count is : 2, 2, 3, 3, 3. Habits: The general configuration of the skeleton indicates an active animal. Ossification is complete except for the carpal s and tarsals, and the limbs are long relative to the length of the body. The lack of prominent tuberosities on the limbs, expected in an animal of small size, indicates that even the largest of these animals was not heavily built. An interesting feature is the length of the hands and feet, much in excess of those of any Permian dissorophids. Apparently this was an adaptation for a coal swamp environment. Little modification in this regard is noted in other portions of the animal's anatomy, however. The great length of the limbs, absence of lateral line canals, and the lack of a highly developed dermal shoulder girdle — associated in other forms with aquatic existence (Wat- son, 1919) — suggests that Ampliihamus lyelli did not habitually Fig. 25. Amyhihamm lyelli. Restoration of skeleton. X -/3- CARROLL: DISSOKOIMIID EVOIvlTIO.V 241 livo ill the water. Supjiortiiij'' tliis is the almost coiriplote ossifica- tion of the skeleton and the ver^- well developed sacral attach- ment. The lonfr, and perhaps webl)ed, feet would have allowed it to traverse readily bogs and shallow pools. As a response to increased aridity, its Permian descendants coiii})letely lost this adaptatioiL Ampiiibamits calliprepes (Steen) Mordcx calliprepes Steen, 1938, p. 260. r have not been able to investijjate personally any of the Nyfany material of possible dissorophid affinities. Nevertheless, the additional knowdedg'e we now have concerning other Penn- sjdvanian species makes it necessary to comment further on those previously described. Three forms from Nyrany were considered by Gregory (1950) to be dissorophids. One is Bicnndon Hninophyes. It is very difficult to conceive of this animal as even a member of the Rhachitomi, much less of the Dissorophidae. The structure of the palate is particularly diffi- cult to reconcile. The shapes of the parasphenoid and pterygoids are vastly different from those of any dissorophid. The ptery- goid, ectopterygoid and palatine all bear numerous large teeth not encountered in dissorophids. The orbits are separated by far too great a distance relative to their size for any known dissorophid. the pattern of sculpturing is different from that of any mem])ers of that family, and the tabular-supratemporal appears as a single bone rather than as separate units. Romer (1950) placed Ricnodon among the lepospondyls. Gregory's inclusion of Mordex calliprepes (Steen, 1938) among the dissorophids is entirely justified. In fact, there is yery little to separate this species from Ampliibamus lyeUi on the evidence of the skull roof and palate. The specimen on which this species is based is just slightly smaller than the British Museum specimen of A. lijelli, so comparison will be made with that form. The differences are primarily in propor- tion. In "Mordex/' the width across the back of the skull table is small compared with the length of the skull, the contact of pre- and postfrontal is larger than in A. lyelli, and the post- parietals are narrower. When comparison is extended to the type of A. lyelli, it becomes apparent that the dimensions of "Mordex" are probably within the range of variation of that species. All the proportional differences, hoAvever, suggest a position slightly closer to A. grandiceps. For this reason, as 242 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY well as the geographical separation of this form, it seems reasonable to maintain it as a distinct species, at least until more is known of the anatomy. There is one additional point of distinction. According to Steen (1938, p. 260), "there is a small pentagonal interfrontal bone present, which, unlike the other dermal bones, is unornamented." It seems possible that this may be only an artifact, especially since it is unsculptured. Romer (1947) suggested "Mordc.r" as a possible ancestor of the trematopsids. While there is nothing to definitely bar it from such a position, it is certainly no closer to that family than any of the other Pennsylvanian dissorophids. It also has a large number of features that separate it from the known Permian trematopsids. The frontals do not extend in front of the orbits to the extent that they do in the Trematopsidae. The skull is not elongated in front of the orbits. The post- parietals are quite small, as is the rear skull table. There is no apparent modification of the external nares. Another form mentioned by Gregory as a dissorophid is a specimen of Limnerpeton laticeps (Fritsch, 1883, plate 36, fig. 1). The immaturity of the specimen prevents any conclusive statement. Amphibamus grandiceps Cope This species was discussed quite thoroughly hy Watson (1940) and l)y Gregory (1950), but in light of the evidence reported here, it is profitable to review certain features of its anatomy. The most important thing to keep in mind concerning the species is the small size and youth of all known specimens. The skull has many features peculiar to young individuals. Among these are the large size of the orbits, pineal foramen, and external nares, the tendencj?^ of the bones to separate, and the simplicity of suture lines. One peculiarity that is not explained in this way is the lack of a suture between the supratemporal and the tabular. Ap- parently this is lacking on both of the extant specimens. Descriptions of two missing specimens, however, do indicate such a suture (Moodie, 1916, p. 128, fig. 26; and Hay, 1900, p. 122). It is almost certain from phylogenetic considerations that the tabular must have been a separate unit as it is in most of the Rhachitomi. On two other points, changes might be made in recent de- scriptions. In the neotype, contrary to ({regory's interpreta- tion, tlie jugal and lacrimal do ai)pear to meet lieiicath the CARROI.I, : DISSOROI'IIID KVOLT'TIOX 248 orbit, (>v('i! if (iiily with a very small coiitacl. In Watson's (Inscription of the Chica^-o specimen he mentioned the existence of a patch of scale-covered skin wliicli lay between the upper and lower jaws on the left side of the skull in al)out the same area as an oi-liit. lie dismissed the idea that this was an ossifica- tion in the upi)(>r eyelid. In view of the condition in A)uphi- hainus hiilli and particulai-ly in Tcrsoniius, it a{)pears tliat this is just what it is, rather tlian part of a covering between the lower jaws. Some of the features reported in earlier descriptions of Amphil)(imu>< (/rand ice ps would separate it distinctly from Auiphihfniuis Ii/elli. Several of these features were only inferred, however, and so may be ignored until they can be checked in moi'e adequately preserved material. Whether there are ribs on the first, second and third vertebrae, as well as aliead of and behind the sacral rib, cannot be determined. CNIIM 2()()(), on which most of the details of Watson's description were based, consists of molds of both sides of the bones, with the bone itself preserved only as a white film which has for the most part been removcMl. In preservation of this kind it is difficult to tell sutures from cracks, and irregularities in the matrix from features of the skull. There is nothing in either this skull or YPM 794 to determine the existence of the peculiar upper jaw joint described by Watson, or the unusual septo- maxilla. A row of palatal teeth such as reported by Watson would be a decidedly unusual character for a dissorophid, and apparently consists of bases of teeth from the broken upper jaw, the ends of these teeth having remained in place in the maxilla to be preserved alongside their own roots. As Watson stated, there is no sign of paired teeth on the vomers, palatines and ectopterygoids ; they are apparently cov- ered either by the lower jaws or by a layer of denticulate "skin" such as is present in A. lyrlli. They may even be absent in such a young animal. Despite the youth of these specimens, several features defi- nitely distinguish them from A. lyelli. The number of marginal teeth is different in the two species but is relatively constant within the mend)ers of each. A. grandiceps has about 48 marginal teeth, while .1. hjelli has about 76, regardless of the size of the skull. The number of presacral vertebrae appears to be less in A. grandiceps, but there is such a disparity in published counts for that species that no definite statement can be made. There are also changes in relative dimensions that 244 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY may hold true for adult specimens of A. grandiceps. The pre- and postfrontals have a broader line of contact in that species than in A. lyelli, and the postparietals are smaller. A feature in which A. grandiceps differs from later dissorophids is the perforation of the stapes. In this species there is a definite hole near the base, while in Broiliellus and Dissorophus it is im- perforate; the condition is not known in A. lyelli or in Ter- som.ius. Arkanserpeton arcuatum Lane An isolated femur was described by Lane (1932) from the Paris shale of Kansas, roughly equivalent to the McAlester shale, at the top of the Pottsville or the base of the Allegheny. He considered that it was an embolomere, but as Romer (1947) has pointed out, it is probably a dissorophid. It is larger than, although otherwise similar to, the femur of Amphihamns lyelli. None of the femora of Pennsylvanian dissorophids is well enough preserved to determine specific relationships. Interrelationships of the Pennsylvanian Dissorophids Compared with the Permian dissorophids, the Pennsylvanian members of the family are few and apparently little diversified. Despite the long time span during which dissorophids are known in the Pennsylvanian, there are at most two genera represented, compared with at least six genera in the Wichita group alone of the Lower Permian. This might be considered only a result of the general paucity of Pennsylvanian deposits were it not for the fact that the genus Amphihamus is known from three deposits of differing age and locality. This suggests that there was truly little diversity of the family in the Penn- sylvanian. The relationships among the three species of Amphihamus cannot be determined definitely, since A. grandiceps is repre- sented only by very young specimens and A. calliprepes is known only from an incomplete skull table. All three may have developed from a common ancestor, or A. grandiceps may have given rise to the other two species. Nothing can be stated concerning the relationships of Arkanserpeton until more ma- terial is available. Tersomius almost certainly evolved from Amphihamns, but it is not known from which species. It is probable that the remainder of the dissorophids evolved from Tersomius rather CARROLL: niSSOROIMIin KVOLfTIOX 245 tliaii (lii'cctly from Ainpliih(n)ii(s since Tcrscnnius lias several features of the hio-hei- dissoropliids not yet acquired by Aynphi- hamua, such as the eiilraiici* of the fi'outal into the margin of the ()i'])it, a well d(n-elo|)e(l intei-iiarial ])it. and a reduced tooth count. It should be noted, ho^vever, that 1\ rso})iius shares most of its primitive features -with A)np]iihaiuus and essentially represents a contiiuiation of a line of evolution established in the early PennsylvaniaiL The critical point in the evolution of the Dissorophidae occurred when the z z LU CL St ephanian Monongohela 1 1 N y ra ny = Linton = Mozon Creek Conemaugh Westphalian D Allegheny C Pons sh B Pottsville A No muna n 1 Fig. 26. Peimsylvanian and Permian stratigrapliy. The chart is liased primarily on Dunbar and others (1960), and ]\Ioore and others (194-i). Correlation of loealities follows Eomer (1947 and 1958), and Panchen and Walker (1960). CAKKOLL: DISSOROI'IIID EVOLUTION' 247 ABBREVIATIONS a ar asc clci CO CO I CO II cof d e ee eo ext f fa fo fv gf li ic icf icg icl icp il inif ilia iiip int is J 1 m nif mrf n nac iicli 111 0 articular ascending process of epiptorygoid position of liasioccii)ital hasisiilicnoid clavick' cleitlirnin coroiioid iiitercoronoid precoronoid coracoid foramen dentary epipterygoid eetopterygoid exoeeipital armor, external series frontal foramen for artery fenestra oralis foramen for vein glenoid foramen humerus intercentrum internal carotid foramen internal carotid groove interclavicle internal carotid passage ilium inframeckelian fossa interna sal internarial pit armor, internal series ischium jugal lacrimal maxilla mandibular foramen median rostral fontanel nasal space for cartilaginous nasal capsule position of notochord nasolacrimal groove otic capsule ol.f oliturator foranuMi p parietal pa prearticular ].(• pleurocentrnm I'f postfrontal I'l palatine pm premaxilla po ])ostorl)ital pos postsplenial pp postparietal ppc palpebral cup prf prefrontal pro l)ro()tic jjrocess of epipterygoid ps para sphenoid pt pterygoid ptf posttemporal fossa pu pubis q quadrate q.i quadratojugal r rib ra radius rem recess for rectus eye muscles sa surangular sc scapulocoraeoid scl sclerotic plates se sphenethmoid set position of sella turcica sgf supraglenoid foramen sni septomaxilla soc supraoccipital sp splenial sq squamosal sr sacral rib St supratemporal sta supraorbital branch of stapedial artery stp stapes t tabular u ulna \' vomer vcl vena capita lateralis I-XII foramina for cranial nerves 248 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY LITERATURE CITED Broili, F. 1904. Pcrmische Stegoeephalen und Reptilien aus Texas. Palaeonto- graphica, vol. 51. pp. l-±9, 51-120. Bystrow, a. p. 1935. Morphologisclie Untersuchungen der Deekknocken des Scliadels der Wirbeltiere. 1. Mitteiluiig. Sehiidel der Stegoeephalen. Acta Zool., vol. 16, pp. 65-141. Case, E. C. 1910. New and little known reptiles and ampliiliians from the Per- mian(?) of Texas. Bull. Amer. Mus. Nat. Hist., vol. 28, pp. 163-181. 1911. Revision of the Amphibia and Pisces of the Permian of North America. Publ. Carnegie Inst. Washington, no. 146, pp. 1-179. Case, E. C, S. W. "Williston, and M. G. Mehl 1913. Permo-Carboniferous vertebrates from New Mexico. Publ. Carnegie Inst. Washington, no. 181, pp. 1-81. Cope, E. D. 1868. Synopsis of the extinct Batrachia of North America. Proc. Acad. Nat. Sci. Philadelphia, 1868, pp. 208-221. 1874. Supplement to the extinct Batrachia and Reptilia of North America. I. Catalogue of the air-breathing Vertebrata from the Coal Measures of Linton, Ohio. Trans. Amer. Philos. Soc, vol. 15. pp. 261-278. 1875. The extinct Batrachia of Ohio. Proc. Acad. Nat. Sci. Phila- delphia, 1875, p. 16. 1895. A batrachian armadillo. Amer. Naturalist, vol. 29, p. 998. DeMar, R. 1961. A review of the family Dissorophidae (amphibians) with em- phasis on the late Wichita and Clear Fork genera. Unpublished Ph.D. dissertation, Dept. of Geology, University of Chicago. Dunbar, C. 0., and others 1960. Correlation of the Permian formations of North America. Bull. Geol. Soc. Amer., vol. 71. pp. 1763-1806. Fritsch, a. 1883. Fauna der Gaskohle und der Kalksteine der Permformation Bohmens. 4 vols. Prague. (1879-1901.) Gaupp, E. 1900. Das Chondrocranium von Laeerta agilis. Ein Beitrag zum Ver- standnis des Amniotenschadels. Anat. Hefte, vol. 15, pp. 433- 596. Gregory, J. T. 1950. Tetrapods of the Pennsylvanian nodules from Mazon Creek, Illinois. Amer. Jour. Sci., vol. 248. pp. 833-873. Hay, O. p. 1900. Descriptions of some vertebrates of the Carboniferous age. Proc. Amer. Philos. Soc, vol. 39, pp. 96-123. CAHHoi.i, : i)iss(»i{()i'iiii) i;v()i,r'n()\ 'J4M Laxe, it. II. nC'.L'. A new stegofeplialian from tlic Pi'niisylv:iiii;iii of Arkjinsas. Kansas Univ. Rci. Hull., vol. 20. vi>. :',!?, :',\7. Laxgstox, W. 1053. Perniiaii aiiipliiliiaiis from Nrw .Mexico. Univ. Calif. PiiM. Gool. Sci., vol. 29, no. 7, i)p. :{49-41(). .MuuDiK, K. L. 1909. Carboniferous air lucatliiiiii vcitclnatcs of Hm' Cnitcd States National Museum, i'roc V. S. X;tt. Mus., vol. 37, pp. 11-28. ]91(i. The Coal treasures AiiipliiMa of North AiiuTica. I'liM. Cariie- ii'ic Inst. Washington, no. 238, ]>\k 1-222. M(ioi;i:, li. ( '., ami others 19-1-4. Correlation of Pennsylvaniaii formations of North America. Bull. Geol. Soc. Amer., vol. 55, pp. G57-70(i. MOUSTAFA, Y. SHAWKI 1955. The affinities of Parioxjis frrricoliis and the ])hyio]>. 149- 176. Paxchex, a. L., and A. D. Walker 1960. British Coal Measure laliyrinthodont localities. Ann. .Mag. Nat. Hist., ser. i;!, vol. 3, no. ;!ii, pp. ?,21-332. ROMER, A. S. 1930. The Pennsylvaiiian tetiajxids of Linton, Ohio. Hull. Amer. Mus. Nat. Hist., vol. 59. pp. 77-147. 1947. Review of the Laliyrinthodontia. Bull. .Mus. Comi). Zool., vol. 99, pp. 1-368. Ht'iO. The nature and relationships of the Paleozoic microsaurs. Amer. .Tour. Sci., vol. 248, pp. 628-654. 19.j8. The Texas Permian redbeds and their vertebrate fauna. In: Studies on fossil vertebrates, edited by T. S. Westoll. London, pp. 157-179. RoMER, A. S., and T. Edixger 1942. Endocranial casts and brains of living and fossil Amphibia. Jour. Comp. Neur., vol. 77, no. 2, pp. 355-389. Sawix, H. J. 1941. The cranial anatomy of Eryops megacephalus. Bull. Mus. Comp. Zool., vol. 86, pp. 407-463. Steex, M. 1931. The British Museum collection of Amphibia from the Middle Coal Measures of Linton, Ohio. Proc. Zool. Soc. London, 1930 (1931), pp. 849-891. 1938. On the fossil Amphibia from the Gas Coal of Nyi-any and other deposits in Czechoslovakia. Proc. Zool. Soc. London, (B), vol. 108, pp. 205-283. 250 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY SUSHKIN, P. P. 1927. Oil the modifications of the niaiidiltular and hyoid arches and their relations to the braincase in the early Tetrapoda. Palaeont. Zeitschr., vol. 8, pp. 263-321. Watson, D. M. S. 1919. The structure, evolution and origin of the Amphibia. — The "orders" Eachitomi and Stereospondyli. Philos. Trans. Eoy. Soc. London, (B), vol. 209, pp. 1-73. 1940. The origin of frogs. Trans. Roy. Soe. Edinburgh, vol. 60, pp. 195-231. WiLLISTON, S. W. 1910. Cacops, Desmospondylns: new genera of Permian vertelirates. Bull. Geol. Soc. Amer., vol. 21, pp. 249-284. 1911. American Permian vertebrates. Chicago, 145 pp. 1914. Broilielliis, a new genus of amphibians from the Permian of Texas. Jour. Geol., vol. 22, pp. 49-56. Wyman, J. 1858. On some remains of batrachiaii reptiles discovered in the coal formation of Ohio, by Dr. J. S. Newberry and C. M. Wlicatley. Amer. Jour. Sci., ser. 2, vol. 25, pp. 158-163. Eeceived Decemljer 15, 1962. PLATES BULLETIN : MUSEr:M OF COMPARATIVE ZOOLOGY i Plate 1. Range of variation in " Aspidosaurus" armor. ^ICZ Hi Rattlesnake Canyon, Admiral Formation. X !• ('AR1{()I.I,: DISSOHOIMIII) KVoLrTIOX I'LATE 2. Ampliihiniiiis lijdii. AMMl (i841, Linton, Ohio. X 1- Bulletin of the Museum of Comparative Zoology HARVARD UNIVERSITY Vol. V.U, No. 8 THE GENUS MIC RATHE N A (ARANEAE, ARANEIDAE) IN THE WEST INDIES By Arthur M. Chickering CAMBRIDGE, MASS., U.S.A. 1' R I N T E D FOR THE MUSEUM June 30, 1964 Publications Issued by or in Connection WITH THE MUSEUM OF COMPARATIVE ZOOLOGY HARVARD UNIVERSITY Bulletin (octavo) 1863 — The current volume is Vol. 131 . Bbeviora (octavo) 1952 — No. 204 is current. Memoirs (quarto) 1864-1938 — Publication terminated with Vol. 55. Johnsonia (quarto) 1941 — A publication of the Department of Mollusks. Vol. 4, no. 41 is current. Occasional Papers of the Department of Mollusks (octavo) 1945 — Vol. 2, no. 28 is current. Proceedings of the New England Zoological Club (octavo) 1899-1948 — Published in connection with the Museum. PublicatioD terminated with Vol. 24. The continuing publications are issued at irregular intervals in num- bers which may be purchased separately. Prices and lists may be obtained from the Publications Office of the Museum of Comparative Zoology, Cambridge 38, Massachusetts. Peters' Check-List of Birds of the World. Volumes 1, 4 and 6 are out of print ; volumes 2, 3, 5, 7, 9, 10 and 15 are currently available. Phylogeny and Evolution of Crustacea. Proceedings of a confer- ence held at Cambridge, Mass., March 6-8, 1962. H. B. Whittingtoii and W. D. I. Rolfe, editors. Cambridge, Mass., 192 pp., 80 figs., 1963. Cloth bound, $6.75. Fishes of the Gulf of Maine, by Henry B. Bigelow and William C. Sehroeder. Washington, viii - 577 pp., 1953. Photo-oifset reprint, $6.50. Publications of the Boston Society of Natural History The remaining stock of the scientific periodicals of the Boston Society of Natural History has been transferred to the Museum of Comparative Zoology for distribution. Prices for individual numbers may be had upon request. Bulletin of the Museum of Comparative Zoology HARVARD UNIVERSITY Vol. 131, No. 8 THE GENUS MICR ATHENA (ARANEAE, ARANEIDAE) IN THE WEST INDIES By Arthur M. Cpiickering CAMBRIDGE, MASS., U.S.A. PRINTED FOR THE MUSEUM June, 1964 Bull. -Mus. Comp. Zool., Harvard Univ., 131(8): 251-281, June, 19G4 No. 8 — The Getvis Micrafhcna (Araneae, Arancidae) in the West Indies By Arthur M. Chickering In connection with my study of the genus Micrathena in Central America (1961) and South America (1960a, b, c), I have recently had the opportunity to study all specimens of the genus from the West Indies now in the collections of the Museum of Comparative Zoology at Harvard College. During the summer of 1958 I had the privilege of studying the West Indian specimens of Micrathena in the extensive collections of the British Museum (Natural His- tory) ; the collections of the American Museum of Natural History have also been made available to me. As a result of my study I have found what I believe to be serious confusion in the identifica- tion of certain species native to the West Indies. It is also obvious that errors of synonymy have been made. I hope this paper will contribute to clarification of the difficulties. I believe there is urgent need for some competent worker to study the whole genus for the entire Western Hemisphere with the intention of publishing a complete revision of the genus that would serve for many years, as Rcimoser's (1917) work did for a genera- tion. This extensive piece of work should be preceded by intensive collecting in the West Indies and, especially, in the tropical regions of South America. I am convinced that such field work would yield excellent results. Not only would new and interesting species be found but much progress could be made in the now difficult prob- lem of correctly matching up the sexes. Acknowledgments extended and appreciation expressed in recent published papers (Chickering, 1960a, b, c, and 1961) are here re- l)eated with my personal gratitude for encouragement over many years. I also wish at this time to express my gratitude and appre- ciation to Dr. W. J. Gertsch, American IMuseum of Natural His- tory, for the loan of a valuable collection. Holotypes of M. levii, M. gertschi, and M. practcrlta will l)e de- posited in the American Museum of Natural History, New York City. Holotypes of all other new species will be deposited in the Museum of Comparative Zoology, Harvard University. Micrathena Sundevall, 1833 Type species, M. clypeata (Walckenaer, 1806), designated l)y Simon, 1895:859. 254 bulletin: museum of comparative zoology MiCRATHENA BRYANTAE sp. nOV. Figures 1-3 Note: Miss Bryant (1940) described briefly a single male from Cuba, but she did not give a specific name to it. I propose regard- ing it as the holotype of a new species and posthumously honoring its discoverer in its specific name. Male holotype. Total length 4.4 mm. Carapace 1.76 mm long; 1.17 mm wide opposite posterior border of second coxae where it is widest; 0.59 mm tall at region of central fovea, which is a well marked circular pit; gently arched from PME to posterior de- clivity, with a pair of distinct dorsolateral foveae in the cephalo- thoracic groove. Eyes. Ocular tubercles moderately well developed. Viewed from above, both eye rows moderately recurved; viewed from in front, anterior row gently recurved, posterior row definitely pro- curved, all measured from center. Central ocular quadrangle wider behind than in front in ratio of 21 : 19, slightly wider behind than long. Ratio of eyes AME:ALE:PME:PLE "= 7:6.5:10:6 (long diameter used where differences exist) . AME separated from one another by a little less than their diameter, from ALE by three times their diameter. PME separated from one another by about three-fifths of their diameter, from PLE by two and one-fifth External Anatomy of Micmlhena Figures 1-3, M. bryantae Fi^.s. 1-2. Two views of the left italpal tarsus, tibia iind jiatella. Fig. 3. Nearly dorsal view of base of left pali'al rvnil)ium with basal tarsal hook, tibia and patella, more enlarged. c;iii(Ki;i{i.\(;: micrathena in thp: west indies 255 times their diameter. Laterals separated IVom one another by slightly less than one-third of the diameter of PLE. Height of clypeus equal to twelve-sevenths of the diameter of AME. Chelicerae. Fairly robust; basal segment about 0.54 mm long; teeth along fang groove not observed because^ of fi'agility of tlu; holotype. Sternum. Scutiform in general; tubercles barely indicated; continued laterally between coxae and posteriorly between fourth coxae as slender sclerites ; fourth coxae barely separated ; surface very finely rugulose. Leg.s. 4123. Width of first patella at "knee"^ 0.16 mm, tibial index of first leg 11. Width of fourth patella at knee 0.15 mm, tibial index of fourth leg 11. Femora Patellae Tibiae Metatarsi Tarsi Totals (All measurements in millimeters) I. 1.43 0.50 0.91 0.99 0.52 4.35 II. 1.37 0.49 0.78 0.85 0.48 3.97 III. 0.85 0.29 0.49 0.52 0.36 2.51 IV. 1.76 0.36 0.98 1.07 0.49 4.66 Palpus 0.33 0.12 0.15 0.66 1.26 Legs with few spines; these mostly broken off from handling. Hook on first coxa and corresponding ridge and groove on second femur lacking. Palpus. See iVIiss Bryant's figure 143 (1940) for one view ol the palpal tarsus and til)ia, and Figures 1-3 in this j^aper for other views. Abdomen. Length 2.73 mm; nearly rectangular in dorsal view (Miss Bryant's fig. 139) ; only moderately flattened; very little, if any, indication of suppressed spines. Color in alcohol. See Miss Bryant's description (1940) . Type locality. The male holotype is from Cuba, Oriente, Los Llanos, 1000-2000 ft. elevation, July 16-20, 1936 (P. J. Darling- ton, Jr.). Other records. A male in the American ]\Iuseum of Natural History collected in Cuba, Soroa, Piiiar del Rio, June 2, 1955 (A. F. Archer) . This specimen was with an immature M. forcipata (Thorell) , and a palpus from another male was found with females of M. forcipata (Thorell) taken in Cui)a, Siboney, Oriente, No- vember 17, 1945 (P. Olayo). 'The term ■knee" is di-fimd u.s tlio place of articulation of the patella with the femur; it IS stiaiglit aiillowish with irregular gray lines and spots. Type locality. Male holotype is from Simla, Trinidad. W.T.. February 26, 1959 (A. M. Nadler). The female is unknown. CIIICKKKIXC: MICKATHKNA IN THE WEST INDIES 269 MiCRATHENA MiLiTARis (Fabi'icius), 1775 Figures 41-50 Amnea militaris Fabricius, 1775. Tlolotyiio from Amoricn. Probably in llin Copenhagpn Natural History Museum. Pleclana viilitari.s. Walokonaor, 1841. Micrathena jnUllaris, Pctrunkcvitch, 1911; Reimoser, 1917; Pelrunkevitcli, 1926, 1930; Bryant, 1940; Roewor, 1942; Bryant, 1945; Bonnet, 1957. Micrathenn armata, Bryant, 1940, 1945 [not Aranea armata Olivier]. Much confusion has existed concerning the status of what is generally regarded as M. inilitarif>. The species has often been filed in collections as M. sagittata and M. forcipata (Thorell), frequently as M. militaris. Miss Bryant regarded M. armata (Olivier) as a synonym of M. militaris, and her conclusion has generally been followed. Dr. Petrunkevitch (1926) may have had the species from the Virgin Islands but his figure of the epigynum does not agree with the specimens I have studied from Cuba, Haiti, and the Dominican Republic. I am not able to clarify the confusion but I can point out certain inconsistencies. I have noted in the epigyna significant differences between typical females from Cuba and specimens from Haiti and the Dominican Republic. These differences may be observed by a comparison of Figures 42-44 with Figures 45-47. Miss Bryant (1940) described what she regarded as the male of the species; some have doubted the validity of her identification, but, after examination of several males from Haiti, the Dominican Republic, and Puerto Rico, taken with females from these same regions, I am ready to accept her conclusion until we have definite evidence to the contrary. I have been unable to find males from Cuba that can be definitely associated with females from that i.'^land, and this again empha- sizes the need for intensive field work in the whole West Indian region. Females. Total length of a specimen from Cuba is 7.61 mm from Aj\IE to posterior border of abdomen between the large posterior spines; total length from anterior border of somewhat gibbous bases of chelicerae to the tips of the posterior spines 11.83 mm. Considerable variation in size of mature females has been noted. The two pairs of spines shown in Figure 41 and in Petrunkevitch's figure (1926) are those to which reference is usually made. Frequently, however, a pair of very small dorso- lateral spines occurs about half way between the bases of the long, posterior spines and the much i^maller, very erect antero- dorsal spines. Less frequently another very small spine occurs at about the base of each of the large posterior spines and is directed 270 bulletin: museum of comparative zoology posteriorly. The promargin of the fang groove on a fairly typical female from Haiti bears five teeth, three of which are relatively small and placed somewhat irregularly; the retromargin bears three teeth of moderate size, regularly placed. The Cuban speci- men chosen to show the features of the epigynum has four teeth on the promargin and three on the retromargin. Females fre- quently have an embolus and accompanying sheath caught in one receptacle, and, occasionally, an embolus in each receptacle, an occurrence first reported for this species by Petrunkevitch in his study of the species in Puerto Rico. The sternum is rugulose; it has three pairs of prominent tubercles and terminates in a prominent, median, extended, conical tul)ercle. The most puzzling variations of all concern the epigynum: Figures 42-44 show its appearance in a female selected from many specimens collected in the Dominican Republic, viewed in three different positions; Figures 45-47 show its appearance in a female collected in Havana, Cuba. My brief study of numerous specimens from several islands in the West Indies certainly suggests the possibility that what is now regarded as one species may, upon further study, be divided into two or more. External Anatomj' of Micrathena Figures 41-44, M. militaris 43 42 Fig. 41. Abdomen viewed from posterior end. Figs. 42-44. Epigynum from below, in posterior view, and in iirofilo from right side, respectively (Fig. 44 more enlarged). chickering: micrathexa in the west indies 271 External Anatomy of Micratheua Figures 45-50, 3/. militnris Figs. 45-47. Ei)igynum from below, in posterior view, and in jirofile from right side, respectively (specimen from Cuba) . Fig. 48. Dorsal view of abdomen of male. Fig. 49. Left palpal tibia. Fig. 50. Left palpal basal tarsal hook. Male. Total length 3.95 mm. The sternum is irregularly rugu- lose; the tubercles, so prominent in the female, are present but much less developed. The teeth along the fang groove differ from those of the female ; the promargin appears to bear four teeth ; the retromargin has four teeth with the distal two set very close together. Figure 48 shows the form of the abdomen as viewed from above. Figures 49-50 show the important features of the palpal tibia and basal tarsal hook. There is no ventral hook on 272 bulletin: museum of comparative zoology the first coxa and no corresponding chitinized ridge and groove on the second femur. Collection records. The male described here and the female from which Figures 42-44 were taken, were collected at Jarabacoa, La Vega, Dominican Republic, May 11, 1959, by Drs. M. W. Sanderson and T. H. Farr. The female from which Figures 45-47 were taken was collected in Havana, Cuba, with no date indi- cated, and was originally identified as M. armata (Olivier). Nu- merous specimens have been studied from Cuba, Puerto Rico, Haiti, and the Dominican Republic. MiCRATHENA NITIDA Sp. nOV. Figures 51-56 The males described below were, for a time, regarded as M. macilenta Chickering, described from Panama, but after a more careful study and direct comparison it now seems quite certain that we are dealing with a new, closely related species. The name nitida is a Latin adjective meaning elegant. Male holotype. Total length 4.03 mm. Carapace 1.6 mm long, 1.3 mm wide opposite interval between second and third coxae where it is widest; with eyes on moderately well-developed tubercles; the moderately well-developed median fovea is nearly a round pit; with no dorsolateral foveae; nearly flat along the mid- dle from PME to posterior declivity; very finely granulated. Eyes. Posterior row only slightly wider than anterior row. Viewed from above, both row^s strongly recurved. Viewed from in front, anterior row nearly straight, posterior row moderately procurved, all measured from center. Ratio of eyes AME:ALE: PME:PLE = 5.5:5:7.5:5. AME separated from one another by slightly more than their diameter, from ALE by slightly less than three times their diameter. PME separated from one another by five-sevenths of their diameter, from PLE by about twice their diameter. LE separated from one another only by a broad line. Central ocular quadrangle wider behind than in front in ratio of about 6:5; about as long as wide behind. Clypeus very receding; height of clypeus equal to about twice the diameter of AME. Sternum. Generally oval in outline with the usual scalloped margin; extended between fourth coxae, which are separated by about three-fourths of their width. Legs. 1423. Width of first patella at knee 0.13 mm, tibial index of first leg 11. Width of fourth patella at knee 0.11 mm, tibial index of fourth leg 11. chickkrixg: mkkathexa in the west indies 273 External Anatomy of Micmlhota Figures 51-56, M. nilida Fig. 51. Body of male, dorsal view. Figs. 52, 54. Left first and second tibia, respectively, ventral view. Fig. 53. Left first femur, ventral view. Fig. 55. Left palpal tibia and tarsus. Fig. 56. Pali)al basal tarsal hook, nearly posterior view. I. 1.25 II. 1.10 III. 0.73 IV. 1.32 Palpus 0.26 Femora Patellae Tibiae Metatarsi Tarsi Totals (All measurements in millimeters) 0.39 0.81 0.70 0.40 3.55 0.37 0.60 0.55 0.35 2.97 0.29 0.37 0.37 0.29 2.05 0.33 0.65 0.70 0.39 3.39 0.12 0.14 0.48 1.00 First leg with many long robust spines on femur and tibia (Figs. 52-53) ; second leg with short robust spines on tibia (Fig. 54) ; first coxa with a ventral hook and second femur with the corresponding prolateral ridge and groove, all moderately well developed; fourth leg with long spines on femur, patella, and tibia, but less developed than on first and second legs; ii few- other spines also present. Two trichobothria observed on the. dorsal side of all tibiae. v .■••.•. 274 bulletin: museum of comparative zoology Palpus. Details rather closely resemble those of palpi of sev- eral other species, but there are specific differences somewhat difficult to represent adequately in drawings (Figs. 55-56) . Abdomen. Much flattened in the manner common among males in this genus; with general form as shown in Figure 51; with obscure indications of suppressed spines at posterior end. Color in alcohol. Legs and mouth parts with varying shades of light brown and yellowish brown. Carapace medium brown with black flecks except for a light stripe extending posteriorly from the median fovea. Abdomen: dorsum yellowish with a nar- row dark marginal stripe on each side; venter yellowish with a narrow dark lateral stripe. Tijpe localitij. The holotype male is from Trinidad, W.I., near Port-of-Spain, April, 1913 (R. Thaxter). Several paratype males are in the collection from Trinidad; one is from Sangre Grande, April, 1913 (R. Thaxter) ; another is from Port-of-Spain, Febru- ary, 1926 (W. S. Brooks) ; the remainder are from the same lo- cality as the holotype and, apparently, taken at about the same time. MiCRATHENA PRAETERITA sp. nOV. Figures 57-63 The holotype described here together with numerous paratypes came to me identified as M. bicolor (Keyserling) . There are super- ficial resemblances, but the details of structure indicate clearly that these specimens do not belong with Keyserling's species. Dur- ing my period of work in the British Museum (Natural History) in 1958 I was able to study Keyserling's types of M. bicolor. This acquaintance has helped me to determine that the species has never been described. The specific name praeterita is a Latin adjective meaning not noticed. Female holotype. Total length, including the slightly extended bases of the chelicerae 4.75 mm. Carapace 1.7 mm long; 1.01 mm wide opposite posterior border of second coxae where it is widest; with indistinct median fovea a short, shallow groove; with no special features; without dorsolateral foveae; cephalothoracic groove very indistinct. Chelicerae. Moderately well developed ; without special modi- fications; typical of females of the genus; fang groove well de- fined; in a paratype the promargin of the fang groove has three teeth, the middle one of which is considerably the largest; the retromargin also has three teeth in this paratype, with the one nearest the base of the fang somewhat the largest. chickering: micrathena in the west indies 275 External Antiloiny of Micralheiia Figures 57-63, M . praeterila 57 Fig. 57. Body of female, dorsal view. Fig. 58. Posterior end of abdomen. Fig. 59. Lateral view of right anterior abdominal spine. Figs. 60-62. Epigynum of holotype from below, in posterior view, and in profile from right side, respectively. Fig. 63. Appearance of epigynum after lo.ss of thin, jirojecting shelf. Maxillae. Short, broad, parallel; also typical of females of the genus. Lip. Wider than long in ratio of about 9:5; does not quite reach to middle of maxillae. I. 1.38 II. 1.28 III. 0.92 IV. 1.65 0.54 4.12 0.53 3.81 0.35 2.59 0.62 4.72 276 bulletin: museum of comparative zoology Sternum. Scutiform in general; sternal suture strongly pro- curved; moderately convex; not continued between coxae; ter- minates in a point at beginning of space between fourth coxae, which are separated by nearly one-fourth of their width. Legs. 4123. Width of first patella at knee 0.21 mm, tibial index of first leg 15. Width of fourth i)atella at knee 0.21 mm, tibial index of fourth leg 14. Femora Patellae Tibiae Metatarsi Tarsi Totals (All measurements in millimeters) 0.53 0.86 0.81 0.48 0.77 0.75 0.35 0.53 0.44 0.51 0.95 0.99 The palpal claw is finely pectinated. Spines are nearly absent from the legs; setigerous tubercles are moderately well developed. Trichobothria have been clearly observed only on the tibiae. Abdomen. Figures 57-59. The three pairs of spines resemble those of some other .species, but there are ahso di.stinctive features among these. Additional spines, frequently found in certain other species, are either rare or lacking altogether in this species. Epigynimi. Figures 60-62 illustrate the holotype. Note that the thin shelf extending ventrally from beneath the ventral border is frequently lacking in paratype, presumably because of break- age. In paratypes that have lost this part the superficial appear- ance of the organ is quite different. Figure 63 is intended to show the appearance of the epigynum in posterior view on an individual that has lost the shelf and probably was also under greater in- ternal pressure than was the holotype. Color in alcohol. The legs are medium brown with variations. Mouth parts are much the same. The carapace is brown with radiating darker streaks and a darker median .stripe leading from PME nearly to the median fovea. All of these marks are i)oorly defined. The sternum is brownish with dark streaks and spots throughout. Abdomen with a w^hite, black and brown color pat- tern difficult to describe adequately; the dorsum has an elongated white spot along the posterolateral side of each of the anterior spines ; a narrow, irregular, brown stripe extends along the median side and dorsal surface of each of the anterior spines and reaches back nearly to the middle of the dorsum; an irregular white stripe extends between the two anterior spines and along the middorsal surface to nearly opposite the bases of the large posterior spines; lateral to these marks there is a mixture of white and brown chickerixg: micratiiena in the west ixdies 277 patches; between the bases of the hirj^e posterior spines there is a transverse row of five white patches; tlie venter has a broad, black stripe extending from the genital groove and dividing to extend dorsally for a considerable distance as a pair of black stripes directed toward the small posterior spines. Considerable variation in the color pattern has been noted among the paratypes as would be expected. For example, the ii'regular white stripe in the dorsum of the holotype may be broken into white spots by encroachment of the brown color that laterally bounds the white: the brown color may be reduced with an increase in the wliite until the latter predominates. Type locality. The female holotype is from St. Augustine, Trinidad, W.I., September 18, 1946 (R. H. Montgomery). Nine- teen paratype females were, apparently, collected with the holo- type. The male is unknown. MiCRATHENA RUFOPUNCTATA (Butler) , 1873 Figures 64-67 Acrosoma rufopunctatum Butler, 1873. Holotype from Janiaica, sex not indicated, in British Museum (Nat. Hist.). Micrathena rufopiDictata Petrunkovitch, 1911; Reimoser, 1917; Roewer, 1942; Bonnet, 1957. The author of this species gave a very inadequate description unaccompanied by figures. Reimoser (1917) merely repeated the original description. There has never been any detailed description published. Female. Total length 5.85 mm, including the bases of the somewhat convex chelicerae and relatively long posterior abdom- inal spines. Carapace: largely overlapped by extended dorsal portion of abdomen and anterior spines; median thoracic fovea a small, rounded pit; with a series of faintly indicated dorsolateral foveae. Eyes. Viewed from above, anterior row moderately recurved, posterior row slightly so. Viewed from in front, anterior row slightly recurved, posterior row moderately jirocurved, all meas- ured from center. Central ocular quadrangle wider behind than in front in ratio of 25 : 21 ; wider behind than long in ratio of 25 : 23. Ratio of eyes AME : ALE : Pi\IE : PLE = 7.5 : 6.5 : 8.5 : 6. AME separated from one another by slightly less than their diameter, from ALE by about four times their diameter. PME separated from one another by nearly seven-sixths of their diameter, from PLE by slightly more than three times 278 bulletin: museum of comparative zoology their diameter. Laterals separated from one another by about one-third of the diameter of PLE. Height of clypeus about equal to the diameter of AME. Sternum. A simple scutiform; sternal suture slightly pro- curved; with anterolateral tubercles moderately developed; with a minute tubercle opposite each coxae 1-3 and another minute tubercle at blunt posterior end, which is not extended between fourth coxae; fourth coxae separated by about one-third of their width. Legs. 4123. Width of first patella at knee 0.25 mm, tibial index of first leg 15. Width of fourth patella at knee 0.21 mm, tibial index of fourth leg 14. External Anatomy of Micrathena Figures 64-67, M . rujopunciata Fig. 64. Body of female, dorsal view. Figs. 65-67. Epigynum from below, in posterior view, and in profile from right side, respectively. Femora I. 1.54 II. 1.45 III. 0.97 IV. 1.76 Patellae Tibiae Metatarsi (All measurements in millimeters) 0.62 1.01 1.08 0.57 0.88 0.95 0.40 0.53 0.55 0.55 0.92 1.10 Tarsi Totals 0.53 4.78 0.53 4.38 0.44 2.89 0.48 4.81 chickering: micratiiena in tiiio west indies 279 Legs with numerous short, slender spines and many setigerous tubercles. Triehohothria observed on tibiae; doubtful elsewhere. Palpal claw finely toothed. Abdomen. General form as viewed from above shown in Figure 64. There are only two pairs of spines and no indication of small accessory spines such as often appear in the genus. The anterior border and spines are extended far over the carapace. Epigynum. In essential features, shown in Figures G5-67, e])igynum closely resembles that of M. mitrata (Hentz), M. cubana (Banks), M. mnrfnrlanei Chickering, M. fidelis (Banks) and probably others. Color in alcohol. The color pattern on the abdomen is distinc- tive. The carapace, mouth parts, and legs are all rich reddish brown with variations. The sternum is dark brown. Abdomen: The dorsolateral sides are bright yellow; this marginal stripe in- cludes the anterolateral spines but stops at the bases of the posterolateral spines; there is also a yellow marginal stripe ex- tending along the posterior border between the two posterolateral spines; the latter spines themselves are rich reddish brown; the remaining dorsal region is grayish, darker around the border, and almost white in the center; the lateral and ventral areas are pre- dominantly very dark brown, almost black; the venter has three pairs of bright yellow spots introduced into the brown back- ground; the most anterior pair of these yellow spots is at the level of the epigynum ; the second pair at about the level of the spinnerets ; the third pair is near the posterior border. I have seen no color pattern like this among the many species in the genus studied during the past several years. Collection records. The original specimens were reported from Jamaica, W.I., in 1873. So far as I have been able to determine, the species has not been reported from that time until the present. Three females in the American Museum of Natural History were taken by Dr. T. H. Farr, Institute of Jamaica, Kingston, Jamaica, W.I., at the entrance to Mt. Diablo Forest Reserve, June 29, 1960. The male remains unknown. MiCRATHENA siMiLis Bryant, 1945 Figures 68-71 Micrathena siviilis Bryant, 1945. Female holotype from Dominican Rppuh- lic, Piierta Plata, 30 August, 1938, in the Museum of Comparative Zoology. This species has been under close scrutiny for some time and its 280 bulletin: museum of comparative zoology validity as a distinct species is still uncertain. Miss Bryant con- sidered it closely related to M. cubana (Banks). It should be re- studied when a large series is available. Three specimens are known to me: the holotype, a paratype female from the Domini- can Republic, Mt. Diego de Ocampo, North Range, 3000-4000 ft. el., July, 1938 (P. J. Darlington, Jr.) ; one female from Dominican Republic, Valle de Polo, Prov. de Barahona, August 18, 1935 (W. G. Hasler). The male remains unknown. The epigynum ap- l)ears quite different than represented by Miss Bryant's figures 8 and 43 (1945). External Anatomy of Micrathena Figures 68-71, M. similis 70 Fig. 68. Posterior end of abdomen from behind. Figs. 69-71. Epigynum from below, in posterior view, and in profile from right side, respectively. BIBLIOGRAPHY Banks, N. 1909. Arachnida of Cuba. Sec. Rept. Centr. Exper. Stat. Cuba, pj). 150-174, 45 pis. BONNKT, P. 1957. Bibli(^f;raphia Araneorum. Toulouse. Vol. 2 (3). CIIICKKRIXC. : MICRATIIKXA I X THE WEST INDIES 281 Bryant, Elizabeth 1940. Cuban s])iders in I he Musouni of Comparative Zoology. Bull. Mus. Comp. Zool.. 86(7) : 249-532, 22 pis. 1945. The Argioi)ida(> of Hispaniola. Bull. Mus. Conip. Zool., 95(4) : 359^18,4 pis. BlITLEK, A. G. 1873. A list of spitlcns of Ur- gtaius Acrosomd, wi(h descriijlions of new species. Proc. Zool. Soc. London, pp. 420-429. Chickering, a. M. 1960a. Three new species of Micmlhcua (Arancac, ArKio])idac) from South America. Breviora, Mus. Comp. Zool., No. 121: 1-11. 19601j. Notes on certain sjoecies of Micrathena (Araneae, Argiopidae) from South America. Breviora, Mus. Comp. Zool., No. 122: 1-7. 1960c. Six now species of Micrathena (Araneae, Argiopidae) from South America with notes on known species. Proc. Zool. Soc. London, pp. 65-89, 90 figs. 1961. The genus Micrathena (Araneae, Argiopidae) in Central America. Bull. Mus. Comp. Zool., 125(13) : 380-470. Fabricius, J. C. 1775. Systema Entomologiae. Vol. II, pp. 434. Keyserling, Graf E. von 1864. Beschreibung neuer und wenig bekannter Arten aus der Familie Orbitelae. Sitzber. naturwiss. Gesell. Isis, Dresden, 1863: 63-98, 119-154, pis. 1-7. 1892. Die spinnen Amerikas. 4. Epeiridae. Nurnberg. Baur & Raspe. Petrunkevitch, A. 1911. A synonymic index-catalogue of spiders of North, Central, and South America. Bull. Amer. Mus. Nat. Hist., 29: 1-809. 1926. Spiders from the Virgin Islands. Trans. Connecticut Acad. Arts Sci., 28: 21-78, 28 figs. 1930. The spiders of Porto Rico. Pt. 2. Trans. Connecticut Acad. Arts Sci., 30: 159-355, 240 figs. Reimoser, E. 1917. Die Spinnengattung Micrathena Sundevall. Verli. zool. bot. Gesell. Wien, 67(%) : 73-160. ROEWER, C. Fr. 1942. Katalog der Araneae. Vol. 1; 1-1040. Simon, E. 1892- Histoire naturelle des Araignees. Deuxieme Edition. 2 Vols. 1903. Librarie Encyclopedicjue de Roret, Paris. Sundevall, J. C. 1833. Conspectus Arachnidum, p. 14 Thorell, T. T. 1859. Nya exotiska Epeirider. Ofvers K. Vet.-Akad. F(3rli.. pp. 299-304. Walcken.^er, C. a., Baron de 1837- Histoire naturelle des inscctes aptercs. 4 Vols. Paris. 1847. (Received March 19, 1963.) Bulletin of the Museum of Comparative Zoology HARVARD UNIVERSITY Vol. 131, Xo. 0 lievised genekic diagnoses of the fossil fishes megalk'hthys and ectosteorhachis (fa:milv osteolepidae). By Keith Stewart Thomson With One Plate CAMBRIDGE, MASS., U.S.A. I'RINTEl) FOR THE MUSEUM JrLY 7, 1964 Publications Issued by or in Connection WITH THE MUSEUM OF COMPARATIVE ZOOLOGY HARVARD UNIVERSITY Bulletin (octavo) 1863 — The current volume is Vol. 131 . Breviora (octavo) 1952 — No. 204 is current. Memoirs (quarto) 1864-1938 — Publication terminated with Vol. 55. JoHNSONiA (quarto) 1941 — A publication of the Department of Mollusks. Vol. 4, no. 41 is current. Occasional Papers of the Department of Mollusks (octavo) 1945 — Vol. 2, no. 28 is current. Proceedings of the New England Zoological Club (octavo) 1899-1948 — Published in connection with the Museum. Publication terminated with Vol. 24. The continuing publications are issued at irregular intervals in num- bers whicli may be purchased separately. Prices and lists may be obtained from the Publications Office of the Museum of Comparative Zoology, Cambridge 38, Massachusetts. Peters' Check-List of Birds of the World. Volumes 1, 4 and 6 are out of print; volumes 2, 3, 5, 7, 9, 10 and 15 are currently available. Phylogeny and Evolution of Crustacea. Proceedings of a confer- ence held at Cambridge, Mass., March 6-8, 1962. H. B. AVhittingtoii and W. D. I. Rolfe, editors. Cambridge, Mass., 192 pp., 80 figs., 1963. Cloth bound, $6.75. Fishes of the Gulf of Maine, by Henry B. Bigelow and William C. Schroeder. AVashington, viii - 577 pp., 1953. Photo-offset reprint, $6.50. Publications of the Boston Society of Natural History The remaining stock of the scientific periodicals of the Boston Society of Natural History has been transferred to the Museum of Comparative Zoology for distribution. Prices for individual numbers may be had upon request. Bulletin of the Museum of Comparative Zoology II A R V A K D U N I \' K H S I 'V Y Vol. 131, No. !) KE VISED GENERIC DIAGNOSES OF THE FOSSIL FISHES MEGALICIITIIYS AND EOTOSTEOKHACHIS (FAMILY OSTEOLEPIDAE). By Keith Stewak'i' Thomson With One Plate CAMBRIDGE, MASS., U.S.A. PRINTED FOR THE MUSEUM July, 1964 Hull. Mils. Comp. ZuoL, H.-iivanl t'liiv., 131 (9) :283-311, July, 19(54 No. 9 — Rcriscd (j( n< He diagnoses of the fossil fishes Megalichthys a?(f/ Ectosteorhachi.s {family Osteolepidae). By Kkith .Stkwakt Thomson i In the course of .studies on the inorpli()I()«^y of the Hhipidistia (fossil fishes of the order Crossopterygii) 1 liave found it neces- sary to enquire into the systematies of certain of the forms concerned, notably Ectosteorhachis and 3Ie(jaliehtJiys (members of tlie family Osteolepidae). The luime Eetosteorhaehis was coined by Cope (LSHO) foi- material of a rhipidistian collected in the Permian "red-beds" of Texas. Cope described the type species, Eetosteorhaehis nitidus, and later (1883) a second si)ecies, E. ciceroneiis, which he dif- ferentiated from E. nitidus by the nature of the surface oiiia- mentation of the dermal bones of the skull. Hussakof (1911j showed that the two forms actually belong- to the same species. Until recently remains of Eetosteorhaehis were rare, but now a considerable amount of material, particularly in the collections of the Museum of Comparative Zoology, is available for study. Eetosteorhaehis has only l)een found in the Lower Permian of the United States, and the principal collections have been made in the Wichita Group (Moran to Belle Plains formations) ; a single jaw in the Museum of Comparative Zoology was recently collected in the Dunkard Group, Lower Permian, of Clarke Mill, Ohio. In 1891 Cope decided that his genus Eetosteorhaeliis was in- distinguishable from the form known as " Megaliehthys" — a common Carboniferous genus well known in the European Coal Measures. In more recent times re-study of Eetosteorhaehis, as Romer (1941) has noted, has led to the suggestion that tliis form is, after all, a distinct genus. The aim of this pai)er is to explore this view, by a comparative anatomical study of the two forms; as will be seen, the conclusion reaclK^l is that Ket- osteorhaehis should be re-established as a valid genus. '^Megalichthys" is a rhipidistian occurring very commonly in the Carboniferovis deposits of Europe, wliei-e it is frequently found in the ironstone shales associated with workable coal seams, and less commonly in the Carboniferous of North America. Un- fortunately, there is considerable confusion concerning the 1 Present address: Department of Zoolojr.v, University College, London. 286 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY nomenclature of this genus and at the end of this paper I have included a discussion of this problem. The name MegalicJithys throughout this study is used in the sense of Smith-Woodward (1891) as is, in fact, the common usage of the name. Several species of MeyalicJithys have been described; the discussion of the genus given below is based mainly on the structure of the type species MegalichtJiys Jiihherti Agassiz. Mcgalichthys coccolepis Young, intcrmcdius Woodward, laticeps Traquair, and macropoma Cope, have been distinguished from M. hihhoii principally on the relative proportions of the maxillae and gular ])lates and such distinctions do not affect our present discussion in any way. During this study, which formed part of my dissertation for the degree of Doctor of Philosophy at Harvard University, I have been greatly assisted by Professor A. S. Eomer. I am also grateful to him for the use of the collections and facilities of the Museum of Comparative Zoology. I am indebted to Professor G. G. Simpson for his criticism of the final section of this paper. I must also thank Dr. E. I. White, Keeper of Palaeontology at the British Museum (Natural History), London, who allowed me to spend several weeks studying in his department during the summer of 1962. Mr. H. A. Toombs of the British Museum (Natural History) and Dr. C. D. Waterston of the Royal Scottish Museum, Edinburgh, have also given me assistance and advice ; I am particularly grateful to the latter for his efforts to identify for me various specimens from the Hibbert Collection in the Royal Scottish Museum. Dr. B. Schaeffer of the American Museum of Natural History. Dr. D. Baird of Princeton University, and Dr. P. P. Vaughn of the University of California at Los Angeles have each loaned me specimens from the collections of their various institutions. I Avas the recipient of North Atlantic Treaty Organiza- tion Science Studentship 3/60/955 from 1960 to 1963 and the Jeffries Wyman Scholarship at Harvard University during 1960/1961 while I was engaged in this study. MATERIALS The material of Ectostcorhachis used in this study comes largely from the collections of the Museum of Comi)arative Zoology and was collected in the "red-beds" of North Central Texas (Wichita Group, Lower Permian). Specimens, including the holotype (American Museum of Natur;il History |A^IXII] THOMSON: MEGALICHTIIYS AM) KCTOSTEOBIIACIIIS 287 7239), were loano(l to me by various iii.st i! ut ions as ac- kuowledfred above. Of the ^enus Mcgalichfhys, several spt'ciiiiciis in the ^liiseiiiu of Comparative Zooloj^^' (MCZ), including' material of the North American species M. macroporihd, were used in this study. However, the majority of the material studied is in the collec- tion.s of the British Museum (Natural History) (P.MXH) ; this includes the specimen (P. 4251(5) descrilx'd by Agassiz (1843) in his definition of the genus (see later for discussion of nomenclature). ECTOSTEORHACHIS Dermal skull roof A As is the case in other Rhipidistia, th(> outer enamel and dentine layers of the dermal bones of the skull of Ectosteorhachis, especially in the ethmoid region, tend often to be fused into a single covering in such a way as to obliterate any external indication of the sutures between separate bones (cf. Westoll, 1936). However, in the collections of the Museum of Comparative Zoology, there are many specimens (especially MCZ 6498, 6499, 8652," 8661 and 8668)* from which this outer layer has been lost due to the process of weathering of the fossils. It has thus been possible to give a more complete descrip- tion of the pattern of the dermal bones of the skull of this genus than may be given for many genera of Osteolepidae. The only published figures of the skull of Ectosteorhachis are those of Hus.sakof (1911), and of Cope and Matthew (1915), but these show few details of the dermal bone pattern. The premaxillary element in Ectosteorhachis corresponds to the bone which in certain other Rhipidistia Jarvik (1942, 1944) has termed a "compound" bone, comprising a true pre- maxilla, a rostral element which encloses the ethmoid commis- sure of the lateral line system, and probably also the first of the series of nasal bones. This element has been given the unwieldy name of "naso-rostro-premaxilla." Jarvik (1942. p. 347) believes that the interpretation of such a unit as a "den- tigerous rostral" (cf. Westoll, 1936, 1937) is probably incorrect. The supi-aorbital lateral line, anterior to the parietal bone ("frontal" of Jarvik), is borne upon a series of four separate 1 Throughout this paper the terniinolojry used for the various dermal elements in the skull will follow the system of .Tarvik (1!)42, 1944) with the exception of the parietal and postparietal hones whicli are termed hy .Tarvik "frontal" and "parietal," respectively. 288 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY nasal elements (Fig. 1) which probably represent a reduction from a row of six or seven nasals (cf. Osteolepis; Jarvik, 1948) of which the first has been incorporated into the premaxil- lary unit. eth.comm s.o.l . - Fig. 1. Ectosteorhachis. Diagrammatic reconstruction of the dermal skull roof in dorsal view. There is a pair of anterior postrostral bones and, posterior to these, a single median postrostral with, in some specimens, a pair of smaller postrostrals lying near its anterior margin, between the median postrostral and the second nasal element. The infraorbital lateral line is borne upon the lachrymal and thence directly on to the naso-rostro-premaxilla. There are no separate lateral or anterior rostral elements associated with it. The single external narial aperture is bounded by two small bones which have been termed the prenarial and postnarial THOMSON: MEGALHII'IIIVS AND ECTOS TKOK 1 1 ACI I IS 289 (Westoll, 1943). The liomology of these bones will be discussed in a later section. Beeau.se of the extent of the posti-ostral bones, the parietal bones occupy a relatively short part of the roof of the ethmoid region. There is no external parietal foramen. The dermo- sphenotics, postparietals, supratemporals, and tabulars are arranged in the normal rhipidistian way (Fig. 1). The dorsal margin of the orbit seems to be formed by two supraorbitals on each side (Fig. 1, s.o.). The cheek plate (Fig. 2A). The cheek plate in Ectosteorhachis is made up of lachrymal, jugal, postorbital and squamosal bones arranged in the normal rhipidistian manner. p,op Fig. 2. Schematic reconstruction of the anterior cheek-plate region. A, Ectosteorhachis, B, Megalichthi/.s. The palate (Fig. 3A). I have only studied the ethmoid division of the palate. The only other rhipidistian in which the palate has been described in detail is Eusthenopteron (Jarvik, 1942, 1944, 1954), a rhizodontid. The palate of Ect- osteorhachis differs significantly from that of Eusthenopteron. The vomers of Ectosteorhachis are almost triangular in shape and do not quite meet in the midline. Each vomer bears a pair of alternating tusks and an anterior ridge of marginal teeth. The parasphenoid seems to consist of two parts: the tooth- bearing ridge which reaches about halfway along the flat ventral surface of the endocranium, and a thin bony lamina which (as described by Komer, 1937) continues forw^ard and lateral to the ridge. The whole is fused solidly to the endocranium. The palato-quadrate complex is exactly comparable, as far as I am able to tell, with that described by Watson (1926) in Megalichthys. The conformation of the endocranial part of the palatal aspect of the ethmoid division of the skull is shown in Figure 3A. A major point of interest is the configuration of the anterior 290 BULLETIN : MUSEUM OF COMPARATR'E ZOOLOGY palatal recesses (Fig. 3A, a.p.r.). These are shallow pits Ijnng between the anterior margin of the endocraniuni and the over- lying dermal bones ; they are separated from each other by posterior medial expansions of the premaxillary bones where each bone bears a stout tusk. When the lower jaws were oc- cluded (as seen in specimen MCZ 9830), these anterior recesses served to receive the tips of a pair of large tusks at the anterior ends of the lower jaw rami (ef. Thomson, 1962). Fig. 3. Ethmoid region of tlie palate. Ventral view. A, Eciosteorliachis, B, Megalichihys. The lower jaws (Fig. 4, A, B, C ; based mainly on specimens MCZ 8641, 8826, 8827). As may be seen in Figure 4A, the outer aspect of the lower jaw does not differ greatly from that of MegalichtJiys (as figured by Watson, 1926). It is made up of the dentary and four infradentary elements — splenial, post- spleiiial, angular, and surangular. These elements are ap- proximately demarked by grooves in the shiny continuous enamel covering on tlie dermal bones (Fig. 4A, gr.). THOMSON: MEGALICHTIIYS AND ECTOSTEORIIACHIS 291 The inner surfaee of the lower jaw is made up of the foUowinj^' elements: deutary, three coronoids, preartieular and articular (Fipnrentl.v a misprint for Holoiit iichiiiK. THOMSON: MEGALICHTIIYS AND ECTOSTKORIIACIIIS 305 large teeth and scales from Burdiehouse (figured by Hibbert and Buckland, see Table 1) as well as the specimen figured by Owen (local it}' unknown). Agassiz finally (1843) described the "Leeds Head" specimen, as it ha.s become known (and other material which he considered to belong to the species M. falcatns), but he did not mention whether or not he still considerd any of the Burdiehouse material to belong to the genus Mcf/ulicJithys. In fact he states only that the localities of Megalichthys are numerous, "on en a decouvert dans le pays de Galles, dans les environs de Manchester, pres de StafiPord et dans les environs de Glasgow." This list may by no means be considered complete, since the actual specimen Agassiz was describing came from Yorkshire. In 1853 Owen described as a new amphibian, Parahatrachus colei, a specimen which later (Young, 1868) was shown to be the maxilla of Megalichthys hibbcrti {scnsu Agassiz). M'Coy (1855) seems to have been the first to realize the anomaly in the nomenclature of Rhizodns and Megalichthys. He noted that, in disregard of the facts of the case, the "Leeds head" was considered to be the type of Megalichthys hibberti and the Burdiehouse specimens were considered to belong to Ehizodus hibberti. M'Coy decided "against my better judg- ment" to "leave it as it is." There is little doubt that the name Megalichthys was originally intended to describe the "big-fish" of Burdiehouse wdiich is now known as Rhizodus. However, there is similarly no doubt that when Hibbert used the name Megalichthys hibberti he meant it to apply to the Burdiehouse remains — the "teeth and certain other osseous remains" mentioned above, and these remains, which included both "Rhizodus" and "Megalichthys" were the true types of Megalichthys hibberti Agassiz in Hibbert 1835. Thus Traquair (188-4) noted that the Burdiehouse material^ still remaining in the genus Megalichthys has priority concern- ing the specific name hibberti, but, having concluded that the Burdiehouse remains of Megalichthys are "different specifically" from the "Leeds head" specimen, and acquiescing to the popular conception that the latter forms the type specimen of Megalich- thys hibberti, he described the Burdiehouse Megalichthys with the aid of new material collected there by Hugh Miller, as the new species Megalichthys laticeps. 1 "Scalos and lionps . . . nctnally fipurpil nnclor that name (^[. hihhrrti) nlona rrith (niv italics, KST) rnnains of Rhi::riftiix l)v I»r. Hibbert" (Traquair. 1884, p. 118). 306 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY The position taken by M'Coy and Traquair has been accepted by Smith- Woodward in his "Catalogue of Fossil Fishes" and by many subsequent authors (not, however, by all, see Hay, 1902; Jordan, 1923; Berg, 1958). There seems no merit in proposing that Rhizodus hibherti Owen be renamed Mcgalichthys hihherti Agassiz in Hibbert 1835; similarly there seems no merit in the proposition that the genus now known as Mcgalichthys Agassiz 1843 be renamed Farahatrachus Owen 1853, with type species clacJananensis Fleming 1835. The common usage has remained unchanged since at least 1855, and has been adopted by no less authorities than Agassiz himself and Smith-Woodward. I propose, therefore, to invoke Rule 23b of the International Code of Zoological Nomen- clature, and formally to request the Commission to stabilise the status quo of Smith- Woodward's "Catalogue" (volume 2, 1891) on the subject. I propose that the "Leeds head" (BMNH no. P. 42ol6) be adopted as the lectotype of Megalichthys hihderti Agassiz 1843, and that the large mandibular tooth figured by Hibbert (1835b, pi. 9, fig. 2) now in the Royal Scottish Museum (no. 1950.38.63) be adopted as the lectotype of Rhizodus hihherti Owen 1840, in place of the specimen originally figured bj' Owen and which is now lost. As a summary of the history of the nomenclature of the Burdiehouse specimens, I have drawn up the following table : Table 1 The Burdiehouse specimens All originally described by Hibbert (1835, pi. 8, figs. 1 to 6, pi. 9, figs. 1 to 10, pi. 10, figs. 1 to 3, pi. 11, figs. 2 to 8) as Megalichthys hihherti Agassiz. now known as Rhizodus now known as Megalichthys 1. Egerton (1837) from Agassiz Egerton (1837) from Agassiz MS " Holoptychius hibhrrti" (1835) "Megalichthys hibhcrtii" 2. Buckland (1837, pi. 27, figs. 11, Buckland (1837, pi. 27, fig. 12 from 13, 14, from Hibbert, 1835, pi. 9, Hibbert, 1835, pi. 9, fig. 10) as figs. 2, 3 and 8) as ' ' ITolnptjictnis "Megalichthys hihherti" hihherti" 3. Agassiz (1843) as "Holnpty- Agnsniz (1843) as " Megalichthys" chilis hihherti Owen, (Bin sod us)" 4. M'Coy (1855) as "Rhizodus M'Coy (1855) as " Fhi-ndus hih- hihherti" herti" 5. Tra(|uair (1884), actual speci- mens not cited. Rcnauied "Mega- lichthys laticeps" 6. Smith-Woodward (1891) lists Smith-Woodward (1891) lists Hib- Ilibbert's pi. 8, fig. 1, pi. 9, figs. bert's pi. 11, figs. 2 to 8, as 2, 3, 9, 10, as "Rhizodus hih- " Megalichthys laticeps" hrrii"; TTibberi 's pi. 8, fig. 2 as ' ' Rh i sod us orna f us ' ' THOMSON: .ME(iALI(IITIlVS AXI) KCTOSTEORITACIIIS 307 LITIOKATUKE CITED Aqassiz, J. L. R. 1835. On the fossil fishes of Scotland. Hop. Brit. Assoc. Adv. Sci., Edinburgh, 4: 646(547. 1843. Keeherches sur les poissons fossiles. Neuchatcl and Soleure, vol. 2, 310 pp. Berg, L. S. 19.18. System der rezenten und fossilcn Fischartigen und Fische. Deutscher A'erlag, Berlin, 310 pp. BiKKS, S. (j. 1914. Mf'cjuUrhtlnjs : a study incorporating the results of work on previously undescribed material. Trans. Nat. Hist. Soe. North- umberland Durham Newcastle, (n.s.) 4: 307-329. BUCKLAND, W. 1837. Geology and mineralogy considered with reference to natural theology. 1st ed. London, 2 vols., 552 pp. Bystrov, a. p. 1950. Microscopic structure of the bones and teeth of the Carbonifer- ous crossopterygian fish Alegalichthys (family Osteolepidae). Dokl. Akad. Nauk. U.S.S.E., 34: 119-121. (In Eussian.) Cope, E. D. 1880. Second contribution to the history of the Vertebrata of the Permian formation of Texas. Proc. Am. Phil. Soc, 19: 38-58. 1883. Fourth contribution to the history of the Permian formation of Texas. Proc. Am. Phil. Soc, 20: 628-636. 1891. On the character of some Palaeozoic fishes. Proc. U.S. Nat. Mus., 14: 447-463. Cope, E. D. and W. D. Matthew 1915. Hitherto unpublished plates of Tertiary Mammalia and Permian Vertebrata. Am. Mus. Nat. Hist., Monograph series, 2. Denison, R. H. 1951. Late Devonian fresh-water fishes from the Western United States. Fieldiana, Geology, 11 (5): 221-260. Egerton, P. DE M. G. 1837. A systematic and stratigraphic catalogue of the fossil fishes in the cabinets of Lord Cole and Sir Philip Egerton; together with an alphal)etical and stratigraphical catalogue of the same species, with reference to their published figures and descrip- tions. Rev. ed., London, 20 pp. Fleming, J. 1835. Notice of the remains of a fish found in connection with a bed of coal at Clackmannan. Edinburgh New Philos. Jour., 19: 314-316. Gross, W. 1941. Uber den Unterkiefer einiger devonischer Crossopterygier. Abh. Preuss. Akad. Wiss., math.-nat. Kl., 7: 1-51. 308 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY Hay, O. p. 1899. On some changes in the names, generic and specific, of certain fossil fishes. Amer. Natural., 33: 783-792. 1902. Bibliography and catalogue of the fossil Vertebrata of North America. Bull. U.S. Geol. Surv., 179: 1-868. HiBBERT, S. 1835a. On the ossiferous beds contained in the basins of the Forth, the Clyde, and the Tay. Rep. Brit. Assoc. Adv. Sci., Edinburgh, 4: 642-644. 1835b. On the freshwater limestone of Burdiehouse, in the neighbour- hood of Edinburgh, belonging to the Carboniferous group of rocks. With supplementary notes on other freshwater lime- stones. Trans. Roy. Soc. Edinburgh, 13: 169-282. Holmgren, N. and E. A. Stensio 1936. Kranium und Visceralskelett der Akranier, Cyclostomen und Fische. In: L. Bolk, et alia, Handbueh der vergleichenden Anatomie der Wirbeltiere, vol. 4: 345-353. HUSSAKOF, L. 1911. The Permian fishes of North America. Carnegie Institute Publ. no. 146: 153-178. Jarvik, E. 1942. On the structure of the snout of crossopterygians and lower gnathostomes in general. Zool. Bidrag., 21: 237-675. 1944. On the dermal bones, sensory canals and pitlines of the skull in Eusthenopteron foordi Whiteaves, with some remarks on E. save-soderherglii Jarvik. K. Svenska Vetens.-Akad. Handl., (3) 21: 1-48. 1948. On the morphology and taxonomy of the Middle Devonian osteolepid fishes of Scotland. K. Svenska Vetens.-Akad. Handl., (3) 25: 1-301. 1950. On some osteolepiform crossopterygians from the Upper Old Red Sandstone of Scotland. K. Svenska Vetens.-Akad. Handl., (4) 2: 1-35. 1954. On the visceral skeleton in Eustlienopteron with a discussion of the palato-quadrate in fislies. K. Svenska Vetens.-Akad. Handl., (4) 5: 1-104. 1962. Les Porolepiformes et I'origine des urodeles. Colloques Internat. du Centre National de la Recherche Scientifique, Paris, no. 104: 87-101. Jordan, D. S. 1923. A classification of fishes. Stanford Univ. Publ. Univ. Biol. Sci., 3 (2): 77-243. M 'Coy, F. 1855. Systematic description of the British Palaeozoic fossils. In: Sedgwick and M 'Coy, The British Palaeozoic Rocks and Fossils. Cambridge, 661 pp. THOMSON : MEGALICHTHYS AND ECTOSTEORHACHIS 309 MlALL, L. C. 1884. On a new specimen of Megaliohthyn from the Yorkshire coal field. Quart. Jour. Geol. See. London, 40: 347-352. Moy-Thomas, J. A. 1935. Notes on the types of fossil fishes in the Leeds City Museum. I and II. Acanthodii, Dipnoi, Crossopterygii and Elasmo- branehii. Proc. Leeds Lit. Phil. Soe. (Sci. Sect.), 3: 111-116. Neave, S. a. 1940. Nomenclator Zoologieus. Vol. 3. Zool. Soc. London. i^RVIG, T. 1957. Remarks on the vertebrate fauna of the lower Upper Devonian of Escuminac Bay, P.Q., Canada, with special reference to the porolepiform crossopterygians. Arkiv. Zool., 10 (6) : 367-426. Owen, R. 1840- Odontography. London, 2 vols., 655 pp. 1845. 1853. Notice of a batrachoid fossil in British coal shale. Quart. Jour. Geol. Soc. London, 9: 67-70. ROMER, A. S. 1937. The braincase of the Carboniferous crossopterygian Megalich- ihys nitidits. Bull. Mus. Comp. Zool., 82 (1): 1-67. 1941. Notes on the crossopterygian hyomandibular and braincase. Jour. Morph., 69 (1): 141-160. Smith-Woodvfard, a. S. 1891. Catalogue of the fossil fishes in the British Museum. Part 2. London, 567 pp. Thomson, K. S. 1962. Rhipidistian classification in relation to the origin of the tetrapods. Breviora, Mus. Comp. Zool., no. 177: 1-12. Traquair, R. H. 1884. Remarks on the genus Mcgalichthys Agassiz, Avith description of a new species. Geol. Mag., (3) 1: 115-121. Watson, D. M. S. 1926. The evolution and origin of the Amphibia. Phil. Trans. Roy. Soc. London, (B) 214: 169-257. Wellbourne, E. D. 1900. On the genus Mcgalichthys Agassiz, its history, systematic position, and structure. Proc. Yorks. Geol. Soc, 14: 52-71. Westoll, T. S. 1936. On the structures of the dermal ethmoid shield of Ostcolepis. Geol. Mag., 73: 157-170. 1937. On a specimen of Eusthenopfrron from the Old Red Sandstone of Scotland. Geol. Mag., 74: 507-524. 1943. The origin of the tetrapods. Biol. Rev., 18: 78-98. Whitley, G. 1940. The Nomenclator Zoologieus and some new fish names. Austr. Nat., 10: 241-243. 310 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY Young, J. 1868. On the so-called labyrinthodont, Parahatrachus (Owen). Trans. Nat. Hist. Soc. Glasgow, (n.s.) 1: 174-176. (Eeceived May 10, 1963) ABBREVIATIONS USED IN THE ILLUSTRATIONS a.d.f. anterior dentary fossa a.e.e. anterior extension of the endocranium ang. angular al.ps. anterior lamina of para sphenoid ant.m.v. anterior margin of vomer a.p.r. anterior palatal recess a.pr. anterior postrostral art. articular a.t. anterior tectal Cl-3 coronoids ch. choana cr.d. crista dentalis d. dentary ds. dermosphenotic d.t. dentary tusk e.n. external naris eth.comm. ethmoid commissure of lateral line system ff>: groove in surface of lower jaw i.o.l. infraorbital lateral line ju. jugal I. lachrymal l.r. lateral rostral m.pr. median postrostral mx. maxilla n. nasal n.c. nasal cavity n.pr? possible united nasal and postrostral n.r.p. na so-rostro-premaxilla pa. parietal p.n. postnarial po. postorbital p.op. preopercular po.s. postsplenial p.pa. postparietal p.pr. posterior postrostral p.pr.n. posterior postrostral united with nasal pr. postrostral pr. art. prearticular THOMSON: MECAI.K II'1'II\S AM) KCTOS'li :()K 1 I A( 1 1 1 prji. preiiarial p.s. parasi)heiioid q.j. quadrato-juKal r.p.^. iiiediaii ridt^c dC pa lasiiliriioiil .1. splenial s.diif/. suraiigular ff.nili. symphysial iiicntal hone .v.". siijiraorbital s.d.l. siiiiraorbital lateral liiic so.t. supraoibito-tt'ctal sq. s(iuaniosal st, siipratempoial t. tabular V. vomer vt. vomerine tusk BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY Plate 1. MegnlicMhys macropomus Copo. MCZ 5143. Lcavemvorth Coal ; Lansing, Kansas. Dorsal view showing (U'liiinl lionos of I'tlimoid division of skull roof. Al)l)rcviations: na., nasal; pa., parietal; pn., jiostnarial; p.pr., posterior postrostral; pr.n., prenarial. Bulletin of the Museum of Comparative Zoology HARVARD UNIVERSITY Vol. 131, No. 10 THE COMPARATIVE ANATOMY OF THE SNOUT IN RHIPIDISTIAN FISHES By Keith Stewart Thomson CAMBRIDGE, MASS., U.S.A. printed for the museum August 12, 1964 Publications Issued by or in Connection WITH THE MUSEUM OF COMPARATIVE ZOOLOGY HARVARD UNIVERSITY Bulletin (octavo) 1863 — The curreut volume is Vol. 131 . Breviora (octavo) 1952 — No. 207 is current. Memoirs (quarto) 18(54-1938 — Publication terminated with Vol. bo. Johnsonia (quarto) 1941 — A publication of the Department of Mollusks. Vol. 4, no. 41 is current. Occasional Papers of the Department of Mollusks (octavo) 1945 — Vol. 2, no. 28 is current. Proceedings of the New^ England Zoological Club (octavo) 1899-1948 — Published in connection with the Museum. Publication terminated v^'ith Vol. 24. The continuing publications are issued at irregular intervals in num- bers which may be purchased separately. Prices and lists may be obtained from the Publications Office of the Museum of Comparative Zoology, Cambridge 38, Massachusetts. Peters' Check-List of Birds of the World. Volumes 1, 4 and 6 are out of print ; volumes 2, 3, 5, 7, 9, 10 and 15 are currently available. Phylogeny and Evolution of Crustacea. Proceedings of a confer- ence held at Cambridge, Mass., March 6-8, 1962. H. B. Whittington and W. D. I. Rolfe, editors. Cambridge, Mass., 192 pp., 80 figs., 1963. Cloth bound, $6.75. Fishes of the Gulf of Maine, by Henry B. Bigelow and AVilliam C. Schroeder. Washington, viii - 577 pp., 1953. Photo-offset reprint, $6.50. Publications of the Boston Society of Natural History The remaining stock of the scientific periodicals of the Boston Society of Natural History has been transferred to the Museum of Comparative Zoology for distribution. Prices for individual numbers may be had upon request. Bulletin of the Museum of Comparative Zoology HARVARD UNIVERSITY Vol. 131, No. 10 THE COMPARATIVE ANATOMY OF THE SNOUT IN RHIPIDISTIAN FISHES By Keith Stewart Thomson CAMBRIDGE, MASS., U.S.A. PRINTED FOR THE MUSEUM AuGu.sT, 1964 Bull. .Mils. ('(iin|i. Z(M)1., Ihirvnnl I'niv., 131 ( 10) :313-357, Aiignst, 1904 No. 10 — The romparativc anatomy of the suoul in rkipidistian fishes By Keith Stewart Thomson^ INTRODUCTION Due mainly to the work of Goodrich and Gregory it is now almost universally accepted that the Rhipidistia (fossil fishes of the order Crossopterygii, in the system of Romer, 1955) are the closest ancestors of the tctrapods. In general it has been assumed that the first tetrapods, the Amphibia, were of mono- phyletic origin, but certain theories of a diphyletic origin have been proposed. It has been argued that, of the living Amphibia, the Urodela and Anura represent two distinct lineages. Also, while the fossil history of the Recent Amphibia is very incom- plete, it has been noted that the two major groups of Palaeozoic amphibians, the Apsidospondyli and the Lepospondyli, have yet to be show7i to have a common ancestor. Both Save-Soderbergh and Holmgren proposed a diphyletic theory whereby the Dipnoi were stated to be the ancestors of the Urodela and the Rhipidistia the ancestors of the Anura. This theory is not now generally accepted. A second di]ihyletic theory is that of Jarvik (1942) who, while rejecting the Dipnoi as possible ancestors, proposed that the Urodela and Anura arose from separate stocks of Rhi- pidistia. It is with this theory that the present investigation is concerned. From a study of the snout anatomy of the Rhipidistia and a review of the anatomy of the snout in other gnathostomes, Jarvik (1942) concluded that the Rhipidistia comprise two separate stocks — the "Porolepiformes" (families Porolepidae and Holop- tychidae) and the "Osteolepiformes" (family Osteolepidae and Rhizodontidae). Jarvik studied the Lower Devonian genus Porolepis as his type of the "Porolepiformes" and the Upper Devonian rhizodontid genus Eusthenopicron as his type of the "Osteolepiformes." He gives a detailed account of the snout anatomy of these two forms and of the differences between them. He considers that the differences he observed indicate a basic split in the Rhipidistia. Further studies (1962) have elaborated this theory. Jarvik claims that the two groups of Rhipidistia gave rise 1 Present address : Departnieut of Z(iolo.u:.v, I'nivcrsity College London. 316 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY independently to tetrapod vertebrates — the " Porolepif ormes " to the TJrodela, and the " Osteolepif ormes " to the Anura and probably to all other vertebrates. Jarvik's evidence for this is that from an extensive review of the snout anatomy in certain Amphibia he concluded not only that the Urodela were funda- mentally different from the Anura, but that the diagnostic fea- tures of distinction between the two ''types" of snout anatomy could be identified in the two "stocks" of Rhipidistia also. Thus he believes that the supposedly "characteristic" natures of the snouts of "porolepiform" and " osteolepif orm " rhipidistians have survived essentially unchanged in the Recent amphibians. In general there has been hesitation in accepting Jarvik's con- clusions because, in the first place, it is only the snout region that has been studied in detail and examination of the entire anatomy might yield different results, and, in the second place, because the comparisons made were rather limited in scope. Of the Amphibia only Salamandra and Rana were discussed in detail, and, even more important, of the Rhipidistia only Porolepis and Eusthenopteron were available for study. The present paper is concerned primarily with the evidence for a basic distinction between the "Porolepiformes" and the " Osteolepif ormes, " for all subsequent phylogenetic hypothesis must rest upon the validity of this proposed dichotomy. For many Rhipidistia there is little material preserved in a fashion suitable for detailed palaeo-anatomical studies, but of the osteolepid genus Ectosteorhachis (previously confused with Megalichthys, see Thomson, 1964) from the Lower Permian of North America, much well preserved material exists. I have used this material to prepare a detailed account of the snout anatomy of Ectosteorhachis. The knowledge gained from this study, together with other information concerning different gen- era of Rhipidistia (0rvig, 1957; Vorobjeva, 1959, 1960a, 1960b; Kulczycki, I960; Thomson, 1962; Jarvik, 1962) which has be- come available since the date of Jarvik's original work, enables us to view the anatomy of the Rhipidistia from a broad and more truly comparative basis. The last section of this paper is a criti- cal re-evaluation of Jarvik's theory in the light of this com- parative study. Since the basis for Jarvik's theory was evidence from the nasal/ethmoid anatomy of the Rhipidistia, the present investigation is naturally centered in this region. This study forms part of the work presented to the Depart- ment of Biology at Harvard University in fulfillment of the TIIOIMSON : KlIll'IDlSTIAN SNOUT 317 requirements for the degree of Doctor of Philosophy. During my studies I have been greatly helped and encouraged at all times by mj^ advisor, Professor A. S. Romer, and I must thank him also for the use of the collections and facilities of the Museum of Comparative Zoology. The staffs of the Palaeontology Preparation Laboratory and the Library at the Museum of Comparative Zoology have helped me with many kindnesses and courtesies. This study was undertaken while I was a recip- ient of North Atlantic Treaty Organization Science Studentship 3/60/955 administered by PI. M. Department of Scientific and Industrial Research, London, during the years 1960 to 1963, and the Jeffries Wyman Scholarship at Harvard University during 1960/1961. MATERIALS AND METHODS The material of Ectosteorhachis used in this study comes from the collection of the Museum of Comparative Zoology at Harvard University. It has been collected in the Lower Permian "red- beds" of North Central Texas; several specimens of this col- lection were used in a previous study of Ectosteorhachis {"Megalichthys") made by Romer (1987). The major part of the study has been made from a particu- larly complete skull (MCZ 8662) from the Belle Plains Forma- tion, "Wichita Group, Archer County, Texas, that was sectioned transversely at one-quarter millimetre intervals by the celloidin peel method. Experiments were made to stain the sections : a saturated solution of Alizarin Red S in 95 per cent ethyl alcohol used after the section had been oxidised by immersion in 0.25 per cent potassium permanganate gave the best results, but in general it was found that direct examination of the unstained section under a microscope was the best method of studying the sections. Wax-plate reconstructions were made of the snout region. I have also used the series of sections made in the horizontal and sagittal planes previously prepared by Dr. Romer (cf. Romer, 1937). Of other Osteolepidae, and of the Rhizodontidae, Porolepidae and the Holoptychidae, I have studied the collections of the Museum of Comparative Zoology at Harvard University, the American Museum of Natural History, the Chicago Natural History Museum, the British Museum (Natural History) and the Royal Swedish Natural History Museum. 318 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY ECTOSTEORHACHIS Skeleton of the Snout Region Dermal hones of the skull roof and palate. A full description of the dermal bones of the ethmoid region of the skull of Ect- osteorhacMs has already been given (Thomson, 1964). As shown in Figure 3, the dermal skull roof consists, in the ethmoid region, of a pair of parietal bones which bear the supraorbital lateral line canals forwards and mesially from the dermosphenotics ; a single median postrostral bone ; paired anterior postrostral bones; a compound naso-rostro-premaxilla (termed "premax- illa" throughout this paper) ; a lachrymal bone; prenarial and postnarial bones ; and a .series of four separate nasal bones which bear the supraorbital lateral lines, on each side, from the parietals forward to the ethmoid commissure with the infraorbital lateral liue. The infraorbital lateral line canal, on each side, runs in a shallow loop, ventral to the naris and the pre- and postnarial bones, in its passage between the lachrymal and the premaxilla. On the palate the vomers are roughly triangular in shape (Fig. 4) and the tooth-bearing ridge of the parasphenoid ends anteriorly at the level of the postnasal wall. The vomers form the posterior margin of an "anterior palatal recess" — a shal- low recess formed between the anterior margin of the ethmoid endocranium and the premaxillae. The expanded bases of a pair of premaxillary "tusks," in the midline, separate the recess into two parts. The functional significance of the anterior palatal recesses will be discussed later. External features of the eyulocranium. The endocranium of Ectosteorhaehis has already been described in some detail by Romer (1937, pp. 18-22). My purpose here is therefore to add to Romer 's account those details of structure not shown in his material, which was incomplete in the nasal region. Figures 1 and 2 show the overall configuration of the endo- cranium. The nasal capsules of Ectosteorhaehis are complete dorsally and laterally except for the foramina for the exit of various canals for nerves from the nasal cavity (e.g. Fig. 1, f.ap.). The anterior wall and the posterior wall of the capsule are pierced by canals for various nerves and vessels (discussed in the next section) ; the lateral wall is broken only by the fenestra endonarina. The median wall of the capsule is formed l)y the solid internasal wall ; this is pierced by the canals carry- ing the olfactory tract and also by several vascular and nervous pathways. THOMSON : HIIIPIDISTIAN SNOUT 319 The roof and very thin side walls of the nasal capsule are, for the most part, fused with the overlying dermal bones. On the medial face of the lateral Avail of the capsule, immediately pos- terior to the fenestra eiidoiiarina, there is a small elliptically- shaped ridge of endocranial bone projecting into the nasal cavity. This ridge, which I have termed the crista lateralis (Figs. 5, 9, c.L), bears on its median face a groove (Figs. 5, 9, gr.c.l.) which, from its relation to the external narial aperture, may have par- tially enclosed the tube for the external naris. The posterior wall of the capsule, in addition to being pierced by the canals which in all probability carried the ophthalmicus superficialis seventh and profundus fifth nerves mentioned by Romer (1937), has a large opening in the ventrolateral corner (Figs. 3, 4, 5, 10 D and E, p.v.f.) — the posteroventral fenestra — the significance of which is rather enigmatical. Jarvik con- sidered a similar fenestra in Eusthenopteron to represent a Figure 1. Ectosteorhachis. Ethmoid eudocranium in dorsal view. 320 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY modified posterior external naris which might possibly be con- nected by means of a duct (the forerunner of the tetrapod naso- lachrymal duct) with the orbital opening. It is not impossible that this fenestra served to permit the passage to and from the nasal cavity of large blood vessels. The ventral wall of the nasal capsule is not preserved in any of the material studied by Dr. Romer or myself. In view of the otherwise excellent preservation of the specimens it seems most likely that the solum nasi was not ossified but was present in the living animal only in a cartilaginous form. The position of the choana may easily be inferred from the relative positions of the vomer, palato-quadrate and the dermal bones of the cheek. The pars autopalatina of the palato-quadrate was inserted into the notch formed between the median part of the postnasal wall and the endocranium (Fig. 2, 7i. pq.). This notch is not lined with periosteal bone like the rest of the nasal region and it is possible that the junction between the endocranium and the palato-quadrate in this region was not a free articulation. pm.t. Figure 2. Ectostcorhachis. Ethmoid endocrauium in ventral view. THOMSON: RIIIPIDISTIAN SNOUT 321 The endocranial and associated cavities. In P^'igures 3 and 4, which show the general configuration of the endocranial cavities, the details of the hypophj-sial region have been restored, without modification, after the account of Romer (1937, figs. 9, 10). The cranial cavity in tlie ethmoid division of the skull of Ectosteorhachis consists of spaces containing the hypophysial and ])ineal regions and the olfactory tracts. Since there is no part of the forel)rain corresponding to the olfactory bulbs, it is as- sumed that the olfactory bulbs are represented by swellings in the canals for the olfactory tracts, as is the case in the Dipnoi (cf. Pinkus, 1895). There is no continuation of the cranial cavity anterior to the point of separation of the two olfactory tracts; the internasal wall contains no large cavities. Immediately anterior to the level of the separation of the olfactory tracts there arises, from the ventral surface of the canal for each tract, a set of fine canals (Fig. 4, cc.mea., c.ana.) that I have interpreted, judging from their position and dis- tribution, as having carried vessels probably connected with the internal carotid artery. There are two sets of canals. A series of smaller ramifying canals pass forwards medial and ventral to the olfactory tract canal and terminate in the highly cancellous internasal wall (Fig. 4, cc. mea.) . A single larger canal immediately separates from the smaller canals and runs forwards (Fig. 4, c.ana.) ventral to the olfactory tract canal; at a point just posterior to the nasal cavity it recombines with this canal. Another set of canals arises from the dorsal surface of the canal for the olfactory tract just posterior to the nasal capsule ; these canals (Fig. 3, c.ni.cut.va., c.l.cut.va.) seem also to have contained vascular elements and extend in three directions in the endocranium. (1) An anterior canal has a short connection back to the canal for the olfactory tract and a stout branch curv- ing forwards over the nasal sac. It has a short cross-connection to the canal for the ophthalmicus superficialis seventh nerve (see below), as it passes through and above the postna.sal wall. According to Romer (1937) there is a complete fusion of the two canals here and thej' enter the nasal cavity together. My material indicates, however, that the canals are distinct from each other and from the nasal cavity. The anterior canal disap- pears in the anterior part of the endocranium medial to the nasal capsule. (2) A median canal (Fig. 3, c.m.cut.va.) passes anteromedially and opens onto the dorsal surface of the endo- cranium below the median postrustral bone of the dermal skull 322 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY roof (Fig. 3, m.pr.). (3) A lateral canal terminates in the lateral part of the endocranium behind the nasal cavity (Fig. 3, c.l.cut.va.). Komer (1937, p. 32) has already noted that the posterior wall of the nasal capsule is pierced by two canals which seem to have carried the ophthalmicus superficialis VII and profundus Figure 3. Ectosteorliachis. Endoeranial cavities and the dermal bones of the skull roof. Dorsal view. V cranial nerves, the canal for the former lying dorsolateral of the canal for the latter. The canal for the profundus V (Fig. 3, c.pr.V) is a short simple tube through the postnasal wall; there is a slight connection within the postnasal wall with the canal for the ophthalmicus superficialis VII. The latter canal is en- tirely separate from the nasal cavity, within the postnasal wall. In addition to the connection with the canal for the profundus V and the anterior vascular canal noted above, there is given off from the canal for the ophthalmicus superficialis VTT the first of THOMSON: KHIPIDISTIAN SNOUT 323 a series of dorsal bi-aiu-hes which pass out of ihc ciKlocraiiiuin (Fig. 1, ff.ros.) and obviously contained branches of the nerve supplying the sense organs of the supraorbital lateral line canal. The canal for the ophthalmicus superficialis VII curves forwards through the roof of the nasal capsule and emerges from the endocranium at about the level of the anterior na.sal wall and thence continues in the space between the endocranium and the dermal bones. The anterior wall of th(> nasal (•ai)su]e is pierced by a series of fine canals (Figs. 3, 4, cc.aa.) which communicate with the palatal recess and the medial surface of the premaxilla. A fine canal (Fig. 3, c.lat.) passes through the posterolateral corner of the nasal capsule from the medial surface of the lachrymal bone without entering the nasal cavity. The medial wall of the capsule is pierced by two nerve canals in addition to the canal for the olfactory tract. The more pos- terior of the two canals (Fig. 3, c.r.ext.) leaves the nasal cavity Figure 4. Ectosteorhachis. Endocranial cavities aud dermal bones of palate. Ventral view. 324 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY just anterior to the canal for the olfactory tract and passes dorsally, anteriorly and medially to open at the foramen apicale on the dorsal surface of the endocranium (Fig. 1, f.ap.). Romer considered that the foramen apicale was the opening of the canal for the ophthalmicus superficialis VII, but the situation of this canal seems to indicate that it contained the ramus exterior of the profundus V nerve (discussion below). The more anterior canal piercing the medial nasal wall leaves the nasal cavity at the dorsal part of the anteromedial recess (discussed below). This canal (Fig. 3, c.r.r.) passes anteriorly to emerge on the anterior margin of the endocranium dorsal to the anterior palatal recess ; it seems to have carried an anterior branch of the profundus V system. Also opening through the medial wall of the capsule is a set of branching canals (Fig. 4, c.mev.) which ramify within the internasal septum. This canal system probably contained a set of veins draining into the nasal cavity. Figure 5. Ectosteorhachis. Nasal cavity. A. Left cavity in anterior view. B. Left cavity in posterior view. Graphical reconstructions from the sectioned specimen. The nasal cavity itself is roughly elliptical in shape with the long axis of the ellipse lying at an angle of about 45° to the anteroposterior axis of the head. The inner surface of the nasal capsule is not ornamented and the only modifications of the otherwise smooth contour of its surface are caused by the pos- terior median recess (Fig. 5, p.rcc.) into which the olfactory tract entered, and an anterior median recess (Fig. 5, a.m.r.) (termed the ventromedial recess by Romer, and already discussed by that author). The crista lateralis broadly separates a choanal THOMSON: KI III'IDISTIAN SNOUT 32') recess from the I'est of the nasal ehaiiiher. The groove on the median surface of the crista lateralis may have borne a short narial tube connecting the naris and the nasal chamber (Fig. 3, Certain of the dermal bones contain cavities which are clearly related to the canals for nerves and vessels which pass through the endocranium. Each vomer is pierced by a medial and a lateral canal (Fig. 4, m.c.v., l.c.v.) which are occasionally branched. There are no cross-connections between the canals, but the lateral canal, on one side of the specimen sectioned, has a dorsal branch which emerges on the dorsal face of the vomer underneath the nasal cavity. Since the solum nasi is not preserved it is not possible to detect whether or not this branch actually connected with the nasal cavity. Neither vomerine canal can be traced posteriorly ; it is as- sumed that the medial canal would have been continued medial to the palato-quadrate complex, between it and the parasphenoid bone, and it probably contained the palatine ramus of the seventh cranial nerve. The lateral canal must have been con- tinued backwards lateral to the choana and between the palato- quadrate and the lachrymal ; this canal probably contained the maxillary ramus of the fifth cranial nerve. The nasal, parietal, premaxillary and lachrymal bones of the skull roof enclose a large canal (Fig. 8, c.l.l.) w'hich, from its pathway over the skull roof, its relation to the course of the canal for the ophthalmicus superficialis VII nerve, and the dis- position of its tine branches relative to the centres and modes of radiation of the dermal l)ones, obviously contained the supra- orbital and infraorbital divisions of the lateral line system. The canal for the infraorbital lateral line, as it passes through the pre- maxillae and lachrymal bones, is surrounded by several smaller canals which branch and ramify with the lateral line canal and with each other. These smaller canals must surely have carried vessels and nerves associated with the lateral line organs, includ- ing, in all probability, the buccalis lateralis branch of the seventh cranial nerve. The only connections between the canal for the infraorbital lateral line and the medial surface of tiie dermal bones occur once in the lachrymal bone and once in the pre- maxilla. 326 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY The Nerves of the Ethmoid Region' The fifth cranial nerve. The ramus profundus of the fifth cranial nerve leaves the cranial cavity through the space between the two divisions of the endocranium (see Romer, 1937). Of the further anterior course of the nerve nothing may be seen until it re-enters the endocranium through the postnasal wall (Fig. 3, c.pr.Y). Within the nasal cavity the nerve probably divided into two main branches, a ramus medialis narium and a ramus lateralis narium (Fig. 6, r.m.n., r. In.), as is the case in the Dipnoi and Amphibia. However, while the presence of a branch- ing ramus medialis narium is shown by various canals through Figure 6. Ectosteorhachis. Reconstruction of the nervous system of the snout. Left in ventral view. Right in dorsal view. Portions of nerve course represented by an endocranial canal drawn in solid black, recon- struction in white. 1 Unless otherwise stated, tlio teriiiinolo<;y used in this section follows the system used by Jarvik (1942). THOMSON: KI 1 U'lDISTIAN SNOUT 327 llu" inedial wall of the nasal capsule, similar direct evidence of the path of the ramus lateralis narium is lacking. The canal which opeii« out of the nasal cavity just anterior to the opening for the olfactory tract (Fig. 3, c.r.ext.) probably contained the "ramus exterior" of the profundus V; tliis nerve j)assed dorsally and medially to leave the endocranium at the foramen apicale. Anterior to this a second branch of the pro- fundus V leaves the nasal cavity through the canal opening into the anterior palatal recess (Fig. 3, c.r.r.). I have termed this branch the "ramus rostralis" of the ramus medialis narium (Fig. 6, r.r.). The canal carrying this nerve has a slight connection with that carrying the ophthalmicus superficialis VII nerve, but anastomosis between these two nerves in this position seems un- likely and the connecting canal probably contained a small vessel. A third set of branches of the ramus medialis narium, which I have termed the "anterior rami" (Fig. 6, a.r.), pass through the anterior nasal wall. Figure 7. Ectosieorhachis. RcconstriR'tioii of vascular system. Left in ventral view, right in dorsal view. Portions of vascular system represented by endocranial canals drawn in solid black, reconstruction in white. 328 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY The ramus maxillaris of the fifth cranial nerve seems most likely to have been contained in the canal passing through the lateral edge of the vomer (Fig.s. 4, 8, l.c.v.). This nerve (Fig. 6, r. max.) thus corresponds to the "r.vot." of Jarvik (1942, fig. 61) and the branch of the maxillary fifth which in EustJienop- teron may have formed a post-choanal anastomosis with the ramus palatinus VII. Whether such an anastomosis existed in Ectosteorhachis can only be a matter for conjecture. Other branches of the ramus maxillaris must have passed to and probably within the dermal bones of the anterior part of the cheek. If there was a ramus infraorbitalis it must have en- tered the nasal cavity at the problematical posteroventral fen- estra or have passed forward entirely outside of the nasal cavity. The seventh cranial nerve. The ramus ophthalmicus super- ficialis of the seventh nerve enters the endocranium through the canal, in the dorsal part of the postnasal wall, described above (Fig. 3, c.ros.VII). As it passes through the endocranium in a curved path corresponding to, but slightly medial to, the path of the supraorbital lateral line canal, the ramus ophthalmicus superficialis gives off a series of fine dorsal branches supplying the lateral line organs. Anteriorly, after emerging onto the surface of the endocranium, the nerve passes forwards and then laterally, curving around to the ethmoid commissure of the lat- eral line system ; however, in this region of the snout it is ex- tremely difficult to trace the finer details of the various nerve pathways. The ramus palatinus VII seems to have been carried in a canal in the medial part of the vomer (Figs. 4, 8, m.cv.). Anterior to the vomer the nerve probably passed into the anterior palatal recess region ; posterior to the vomer it probably passed between the palato-quadrate and parasphenoid bones (Fig. 6, r.pal.). Since the infraorbital lateral line is well developed in Ect- osteorhachis, the ramus buccalis lateralis VII must also have been present. The path of the infraorbital lateral line in the nasal region (see Thomson, 1964) curves ventrally below the circum- narial bones, and thus in this region the lateral line canal is morphologically ventral to the level of the solum nasi. This being the case, it is unlikely that the ramus buccalis lateralis would have passed within the nasal cavity as it does in the genus Eusthenopteron (Jarvik, 1942) ; furthermore, only in two places, one within the lachrymal bone and one at the very tip of the premaxilla, is there any connection between the canal for the THOMSON : RHIPIDISTIAN SNOUT 329 infraorbital lateral line and the medial face of the bones contain- ing it. (Conceivably the anterior of these two connections served to pass branches of the ophthalmicus superficialis VII to the infraorbital part of the ethmoid commissure.) We have noted above that the canal for the lateral line is, in this region, sur- rounded by a set of smaller anastomosing canals also contained in the body of the dermal bones, and we must conclude that the ramus buccalis was most likely to have been carried in one of these canals. The Vascular System of the Ethmoid Region Arterial system. Romer (1937) has already described the arrangement of the internal carotid, palatine, and ophthalmic arteries in the hypophysial region of Ectosteorhachis; the fur- ther anterior courses of the palatine and ophthalmic arteries can- not be traced in the fossils. After it has entered the cranial cavity the internal carotid can only be traced by the paths of those of its branches which subsequently leave the cranial cavity. The canals for such branches have been described above. A prominent set of branches (Fig. 4, cc. mea., c.ana.) appears to have passed out from the ventral surface of the canal for the olfactory tract just anterior to the separation of the two tracts. A set of three or four median ethmoid arteries (Fig. 7, mca.) ramify through the median part of the ethmoid endocranium. They pass right up to the tip of the endocranium, but their most anterior passage is very difficult to follow, since the endocranial bone in this region is extremely cancellous; accordingly I have restored them (Fig. 7) only in a diagrammatic fashion. A single and rather larger canal branch- ing from the endocranial cavity at the same point (Fig. 4, c.ana.) also seems to have contained an artery, which I have termed the anterior nasal artery. This artery passes forwards beneath the olfactory tract right up to the nasal region where its canal rejoins that for the olfactory tract and presumably the artery enters the nasal cavity thereby. The set of canals which branch off from the canal for the olfactory tract dorsally, just posterior to the nasal region, seem most likely to have contained arterial vessels also. I have termed these the cutaneous arteries; there are three main elements, anterior, median and lateral. The anterior cutaneous artery passes forwards dorsal to the olfactory tract and curves over 330 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY the nasal region, following approximately the path of the supra- orbital lateral line canal (Fig. 7, a.cut.va.). Immediately after the separation of this artery from the canal for the olfactory tract there is a short connection back to this canal (Fig. 7, olf.c.) which may have held a vessel. The series of short connecting canals between the canals for the anterior cutaneous artery, the ramus ophthalmicus superficialis VII and the profundus V may also have carried branches of this anterior artery. The median cutaneous artery passes anteromedially towards its fellow of the opposite side (in my material the canals did not appear to meet as Romer, 1937, had described), and terminates under the pos- terior part of the median postrostral bone. The lateral cutaneous artery terminates in the lateral endocranium posterior to the nasal capsule. Venous system. There are fewer canals for the passage of veins in the ethmoid region than for arteries. A set of branching canals opening into the anterior part of the posterior median recess of the nasal cavity (Fig. 4, c.mev.) seems to have contained a set of venous vessels draining the internasal part of the ethmoid endocranium. The finer branches of these "median ethmoid veins" which are not shown in the restoration (Fig. 7) seem to terminate in the same general region as do those of the median ethmoid arteries. The wall of the posterolateral corner of the nasal capsule is pierced by a canal which may also have contained a small vein, the lateral nasal vein. This does not enter the nasal cavity (Fig. 3, c.lat.), but passes from the space between the dermal bones of the skull roof to the orbital cavity. Since the arterial supply to the nasal cavity seems to have been well developed, there must have been a substantial venous system draining the nasal chamber. This is borne out by the fact that the veins draining the internasal wall also pass into the nasal chamber. There are two alternative routes by which veins may have left the nasal cavity : either they passed alongside the profundus nerve in its canal through the postnasal wall, or they passed through tlie posteroventral fenestra. There is no way of deciding between these alternatives. It may, however, be noted that the posterior opening of the canal for the presumed lateral nasal vein is in the same general region as the posteroventral fenestra, and in the absence of some other acceptable ex]>lanation of the function of the posteroventral fenestra, the possibility that it served for the passage of vascular elements should not be ignored. THOMSON: RIIllMDISTIAN SNOUT 331 As a filial note on the vaseular system it should be noted that the canals piercing' the antcrioi- wall of the nasal capsule may have contained vessels as well as nerves. DISCUSSION The Ethmoid Endockanium The ethmoid endocraiiiiim has boon described in the folloAving i-hipidistian g'onera : Ecfostcorhachis (Komer, 1937, 1941); Eus- thenopicron (Bryant, 1919; Stensio, 1922; Holmgren and Sten- sio, 1936 ; Sternberg, 1941 ; Jarvik, 1937, 1942, 1954) ; Glypiolepis (Jarvik, 1962) ; T'andcrichfhys (Vorobjova, 1960a) ; Flatycepha- lichthys (Vorobjova, 1959) ; Porolcpis (Jarvik, 1942; Kulczycki, I960); Rhizodopsis (Watson and Day, 1916; Save-Sodorbergh, 1936). More l)riof accounts of those and other genera are also to be found in the literature. Romer (1937) compared the endocranium of Ectosteorhachis with that of those forms then known. To this comparison further points may be added, as below. Antei'wr palatal recesses.^ In both Ectosteorhachis and Mcga- lichthys the anterior palatal recess is divided into two parts by posterior expansions of the premaxillae in the midline. In Mega- lichtliys (Thomson, 1964), division is aided by a "buttress" from the anterior part of the endocranium which fits up against the expansions of the premaxillae. In Panderichthys (also an osteolepid, see Thomson, 1962), the buttress of the endocranium is present but not the premaxillary expansion (see Vorol)jeva, 1960a, fig. 1). In the rhizodontid Easthcyiopteron the anterior palatal recess is undivided. In Porolepis (Porolepidae) and Holoptychms (Holoptychidae) the anterior palatal recesses are paired and entirely separate from each other. Each recess con- sists of a cavum prenasale which corresponds to the anterior recess in Osteolepidae and Rhizodontidae, and a cavum inter- nasale which extends as a shallow depression under the ventral surface of the endocranium (Jarvik, 1942). The two cava inter- nasalia are separated by the anterior part of the parasjjhenoid ; the cava prenasalia are separated by a ridge of the oiulocranium which may correspond to the "buttress" found in some Osteo- lepidae. lAlso described l).v the terms "apieal iiits." "anterior palatal fenestrae." 332 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY Jarvik (1942) considered that these anterior palatal recesses in Rhipidistia contained glandular structures homologous with the various intermaxillary glands found in Recent Amphibia. It had already been suggested, however, that these recesses served for the reception of large "tusks" of the lower jaws when the jaws were occluded (Holmgren and Stensio, 1936; Romer, 1937). Recent work by Kulczycki (1960), Thomson (1962), and Jarvik (1962) has confirmed this view. The characteristic shape of the recesses in the Porolepidae and Holoptychidae reflects merely the nature of the teeth at the tips of the lower jaws which, in these families (0rvig, 1957; Jarvik, 1962), take the form of a pair of tooth whorls. Pars ethmoidalis cranialis. Jarvik (1942) stated that in Porolepis and typically only in the Porolepidae and Holoptychi- dae, the cranial cavity in the ethmoid endocranium is continued anteriorly, beyond the point of separation of the canals for the two olfactory tracts, as a large space — the ' ' pars ethmoidalis cranialis." This feature, he stated, was not present in the Osteolepidae or Rhizodontidae. The inference in Jarvik 's work (cf. Jarvik, 1942, fig. 45 A) is that the pars ethmoidalis cranialis contained the hemispheres of the forebrain which were situated anterior to the point of origin of the olfactory tracts. Jarvik thus supposed that the brain of Porolepis corresponded in its morphology to that of an urodele such as Salamandra (cf. Francis, 1934, pi. 9, figs. 51, 52), as opposed to that of other tetrapods and of Eusthenopteron which lack the pars ethmoidalis cranialis and in which the olfactory tracts are given off from the very anterior tip of the forebrain. A review of the evidence, however, shows that the pars eth- moidalis cranialis does not occur in any consistent manner in the Rhipidistia. Kulczycki (1960) reported that it was absent in the material of Porolepis he studied^ and Vorobjeva (1960a) stated that this cavity was present both in the osteolepid genus Pan- derichthys and the rhizodontid genus Platycephalichthys (see Thomson, 1962). When one further bears in mind that the cavity in the endocranium does not necessarily reflect the exact con- figuration of the brain contained therein, Ave must conclude that it is far from certain that a structure as inconsistent as the pars ethmoidalis cranialis contained any part of the cerebral anatomy. iSome of Kulczycki's oonolnsions must be trcjitert with roscrvatinn, siiico liis material consisted only of natural casts. THOMSON: KIIIIMDISTIAN SNOl^T 333 The nasal caj)sules and nasal cavity. The nasal capsule has been described in detail only in Eusthenopteron and Porolepis (Jarvik, 1942; cf. Kulczycki, 1960). Jarvik concluded from his studies that the nasal cavity in Porolepis was fundamentally different from that of Eustlunopicron; in the following discus- sion I have compared Ectosteorhachis with both of these genera to determine whether or not this distinction may be maintained in the light of a wider comparison. The nasal capsule aiid nasal cavity in Eusthenopteron (Jarvik, 1942, pp. 464-467) have a complicated configuration. The medial wall of the capsule, as in Ectosteorhachis, bears two prominent recesses, an anterior one — termed by Jarvik the ventromedial recess — which is homologous with the anteromedial recess in Ectosteorhachis, and a posterior recess into which, as in Ect- osteorhachis, the olfactory tract enters. The prenasal wall bears two horizontal ridges which were con- sidered by Jarvik (1942, p. 443) to divide the anterior part of the nasal chamber into various recesses. A lateral horizontal ridge runs from the middle of the prenasal wall onto the lateral nasal wall; a smaller and more medial "crista intermedia" runs to the anterior corner of the medial wall of the cavity. Neither of these ridges is represented in Ectosteorhachis. The lateral wall of the nasal capsule of Eusthenopteron bears a thick ledge anterior and ventral to the external narial aperture and projecting as a flange into the nasal cavity. This large structure is termed by Jarvik the "processus intermedins"; its anterior part connects with the lateral horizontal ridge of the prenasal wall. A process from the lateral rostral dermal bone projects onto the processus intermedins and into the nasal cavity as a slip of bone — the processus derminterniedius. These two processes do not have any direct equivalents in E ctosteorhachis ; the possible homology of the processus intermedius with the crista lateralis of Ectosteorhachis is discussed below. In Porolepis (Jarvik, 1942, pp. 367-372, esp. figs. 40, 42 ; Kul- czycki 1960, pp. 74-75, 86-88, fig. 3) there are three main ridges on the inner surface of the nasal capsule, all on the lateral wall. Again, whether these ridges actually reflect any functional divi- sion of the nasal sac is uncertain. The most prominent ridge runs from the anterior external naris to the communal opening for the posterior external naris and the choana. It separates the narial openings from the choanal opening, and, being a quite high ridge, has been supposed by Jarvik (1942, p. 402) to have 334 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY divided the lateral part of the nasal sac into two recesses, the more ventral of which he homologises with Jacobson's organ of urodeles. Jarvik terms this ridge, in accordance with the sup- posed relation with the Urodela, the crista rostro-caudalis. Kul- czycki (1960), however, believes that the ventral recess so delimited is merely a chamber containing the choaua and he terms the ridge "crista subnarina" to avoid hypothetical con- siderations of phylogeny. The two other ridges on the lateral nasal wall of Porolepis are the crista orbito-rostralis which runs from the endochoanal notch to the anteroventral margin of the anterior external naris, and a thickening of the ventral rim of the fenestra endonarina anterior which Kulczycki, supposing it to be homologous with the similar structure in Eusthenopteron, terms the process intermedins. The crista orbito-rostralis is not present as such in either Ectosteorhachis or Eusthenopteron, but it is interesting to reflect upon the question of the relationship of the crista subnarina (crista rostro-caudalis) of Porolepis to the crista lateralis of Ectosteorhachis. Both structures are situated anterior to the (anterior) external naris and pass backwards dorsally to the choana, separating the choanal recess from the main nasal cham- ber : they seem quite likely to be homologous structures/ The crista lateralis is lacking in Eusthenopteron, but in this genus the processus intermedins (and dermintermedius) has taken over the function of separating the choana and external naris. We have already noted, above, a possible homologue of the processus intermedins in the thickening of the ventral mar- gin of the anterior naris of Porolepis, and it is possible to set up the following scheme by which the various characteristic ar- rangements of the nasal cavity in Porolepis, Eiistlienopteron and Ectosteorhachis may be related one to another. It seems likely that the ancestral form linking the early poro- lepid fishes to the later Devonian Osteolepidae and Rhizodontidae was a primitive osteolepid with the external naris situated fairly far forward; there may even still have been two external nares, as has been reported for PawcZeric^i/iiy.s (Vorobjeva, 1960a). The ventral rim of the narial aperture (s) was probably enlarged as a thick ridge extending backwards to separate the naris from 1 If .Tarvik is correct in believing tliat tlie posteroventral fenestra of Eusthenopteron (and Ectosteorhachis) corresponds to tlie posterior external naris, tlie crista lateralis would have the same relations with the anterior naris, choana, and posterior naris as the crista subnarina in Porolepis. THOMSON : KIIIPIDISTIAN SNOUT 335 tlie elioanal rrccss. This ri(l<>-(' would correspond to the crista siibnariiia (crista rostro-caudalis) of Porolepis and also to a process intermedius. In the Devonian Osteolepidae the more anterior part of the ridge was probably developed into a processus intermedins and this may even have been overlain by a processus dermintermedius from the lateral rostral bone. In the later Osteolepidae the more posterior part of the subnarinal ridge developed as the crista lateralis ; this change is probably related to a nugration of the narial aperture backvrards. There is no dermal process comparable to the processus dermintermedius, and indeed, in EctosicorhachiH, the part of the lateral nasal wall hearing the crista lateralis is overlain by the postnarial bone (= tectal of Osteolepis, see Thomson, 1964) rather than by that part of the prenarial bone which corresponds to the lateral rostral bone. The Rhizodontidae seem to have developed from the Osteolepi- dae. In the rhizodontids the naris has retained its relation to the lateral rostral bone, the processus intermedius is well developed, and the posterior part of the subnarinal ridge is lost. The proces- sus dermintermedius is well developed and may extend onto the prenasal wall of the nasal capsule (Jarvik, 1942). We may con- clude that the ethmoid region of the endocranium is apparently constructed according to a single general pattern in Porolepis, Eusthenopteron and Ectosteorhachis. Furthermore, the osteo- lepid Ectosteorhachis is observed to differ from the rhizodontid Eusthenopteron no le.ss greatly than either of these genera differs from the porolepid Porolepis. The Nervous System of the Snout Details of the presumed course of the various nerves of the snout region of Rhipidistia have been given for the following genera only: Porolepis (Jarvik, 1942; Kulczycki,^ 1960); Eus- thenopteron (Jarvik, 1937, 1942) ; Ectosteorhachis (Romer, 1937). Details of the foramina for the profundus V and ophthal- micus superficialis VII nerves of Osteolepis and Rhizodopsis are given by Watson (1926) and Save-Soderbergh (1936), respec- tively. The fifth cranial nerve: ramus profundus. In Ectosteorhachis, Meejalichthys, Osteolepis, Rhizoelopsis, and most species and specimens of Eusthenopteron, the profundus V enters the nasal iQiily the better based of Kulczycki's conclusions are considered here. 336 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY capsule by means of a single foramen in the postnasal wall. In Porolepis, according to Jarvik (1942), the profundus branches within the orbital region so that two or more rami enter the nasal capsule through separate foramina in the postnasal wall. Ac- cording to Kulczycki (1960), the profundus in Porolepis branched within the postnasal wall itself ; this is reported to be the case also in some specimens, at least, of Eusthenodon {Eus- thenopteron) wenjucovi (Jarvik, 1937). It must be presumed that in all genera of Rhipidistia the profundus branched either inside or outside the nasal cavity to innervate both the mesial and lateral part of the na.sal cavity, but that the actual site of the branching is somewhat variable. There were most probably two main branches of the profundus within the nasal cavity — the ramus medialis narium and the ramus lateralis narium. In all cases the ramus medialis narium is the better developed, innervating, in addition to the nasal ap- paratus, the septum nasi and the anteromedial parts of the snout. In Eusthenopteron and Ecfosteorhachis the only branch of the profundus V to pass out through the dorsal surface of the endocranium is the ramus exterior. In Porolepis, according to Jarvik (1942), the profundus V leaves the nasal cavity through several fine canals which pierce the dorsal wall of the nasal capsule. One of the canals he described (1942, fig. 43, c.cut.va.) is homologous with the ramus exterior but, according to Kulczy- cki (1960), the remainder of these fine canals actually belong to the superficial ophthalmic branch of the seventh cranial nerve and do not arise from the profundus V which is very similar to that of other Rhipidistia. AVe have seen that the ramus medialis narium in Ecfosteo- rhachis has a number of medial and anterior branches and these are comparable to the branches of this nerve in Ensihenopteron (cf. Jarvik, 1942, fig. 61). In Jarvik 's restoration (1942, p. 376) the ramus medialis narium of Porolepis left the nasal cavity only by means of the dorsal branches mentioned above, but Kulczycki 's restoration (1960, fig. 5) includes one anteroventral canal open- ing into the anterior palatal recess of Porolepis which seems to correspond to the naso-basal canal (carrying a terminal branch of the ramus medialis narium through the prenasal wall) in Eusthenopteron and Ectosteorhachis (Jarvik, 1942, fig. 60, cvn-b; cf. this paper Fig. 3, cc.aa.). As restored by Jarvik, the ramus lateralis narium in Porolepis has branches which leave the nasal capsule through the lateral THOMSON : HIIIPIDISTIAN SNOUT 337 nasal wall (Jarvik, 1942, fig. 42A, ec.pr.l.) ; comparable ele- ments are lacking in Eusthcnopteron and Ectostcorhachis. Jarvik also described in Porolcpis a third branch of the profundus system which enters the ventrolateral part of the postnasal wall through the "orbitorostral i)assage" (1942, fig. 42 B, c.cr.). After passing along the ventral surface of the nasal sac this nerve leaves the nasal cavity at a foramen in the prenasal wall, but apparently does not pierce this wall. Kulczycki (1960) found no traces of the orbitorostral passage in his material of Porolepis, but he did find a blind canal leading from the nasal cavity into the prenasal wall ; thii> canal, which Kulczycki terms the ' ' para- apical canal," has, however, a different orientation from that c.l.I, A. #27 #29 C. #33 D. #36 Figure 8. Ectosteorhachis. Right nasal cavity, anterior division. #27, at tip of snout; #29 showing anterior margin of vomer; #33 showing anterior margin of external naris; #36 through naris. 338 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY described by Jarvik, and in Kulczycki's opinion could only have contained a blood vessel. We may conclude that the pattern of the ramus profundus V is essentially similar in all Rhipidistia. Fifth cranial nerve: ramus maxillaris. Jarvik (1942) stated that in Porolepis this nerve did not reach as far anteriorly as the nasal region but terminated in the orbit. Kulczycki, however, claimed that there is evidence, in the form of a groove in the lateral nasal wall (Kulczycki, 1960, p. 92), that there was a truncus infraorbitalis extending into the nasal region. In Eusthenoptero7i, Jarvik (1942, p. 477) traced certain branches of the ramus maxillaris but only part of his restoration is based upon the positive evidence of endocranial canals. AVhat little I have been able to discover of the ramus maxillaris in Ectosteorhachis shows that it is generally similar to that of Eusthenopteron, but in most major respects our knowledge of this nerve in Rhipidistia is rather unsatisfactory. Figure 9. Ectosteorhachis. Right nasal cavity, median division. #39 througli ijosterior part of external naris; #44 through crista lateralis; #46 and #47 showing beginning of entry of the olfactory tract canal into the posterior median recess. THOMSON: Kllll'IDlSTIAN SNOUT 339 The seventh cranial nerve: nniiKs ophfJialmicus super ficialis. Ill Eusthcnopieron this ramus passes from the orbit through the postnasal wall and out onto the dorsal surface of the endoeranium in a canal which has no connection Avith the lumen of the nasal cavit3^ In EcfosfcorJiachis the path of the nerve is exactly the same, although Roiiier (19.37, fig. 8) mistakenly described the nerve as entering the nasal cavity. In both genera there may be, within the postnasal wall, a small canal connecting this nerve canal with that for the profundus V. According to Jarvik's (1942) interpretation of the structure of Porolcpis, the ramus ophthalmicus superficialis does not enter the nasal cavity, but Kulczycki (1960) presents evidence that the nerve does enter the cavity, either via a separate canal of its own or through that for the profundus V nerve, and that it passes along the dorsomedial part of the nasal cavity giving off branches through the endoeranium to the supraorbital lateral line canal. These branches are the ones that Jarvik (see above) attributed to the profundus V nerve. Seventh cranial nerve: ramus huccalis lateralis. Nothing is known concerning this nerve in Porolepis. Jarvik believed that it might have passed through the orbitorostral passage (the exist- ence of which has been disputed by Kulczycki). The situation in Eusthcnopteron is also vague although Jarvik (1942, pis. 11, 12 and 13) described a gap between the dermal bones and the nasal capsule in which such a nerve might have passed. Ecto- steorhachis differs from Ensthenopteron in that the infraorbital lateral line canal is situated ventral to the level of the solum nasi, and the rather meagre evidence available indicates that the nerve may have been contained in the dermal bones of the anterior cheek region. Seventh cranial nerve: ramus palatinus. This nerve seems to have occupied exactly the same position in Porolcpis, Ensthenop- teron and Ectosteorhachis. Anastomoses in the nervous system. The two main groups of living Amphibia, Anura and Urodela, are characterized and may be distinguished by distinct patterns of anastomoses between the palatinus VII, maxillaris V and profundus V nerves (e.g. Cogliill, 1902) . Jarvik has attempted to show that the Rhipidistia of the families Porolepidae and Holopt.vchidae agree in this respect with the Urodela, and that the families Osteolepidae and Rhizodontidae agree wdth the Anura. A main point in Jarvik's thesis is the position of the anastomosis between the palatinus 340 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY VII and the maxillaris V nerves, behind the nasal capsule in the Anura and medial to the choana in the Urodela. Unfortunately, the evidence concerning possible anastomoses in the Rhipidistia is rather incomplete, although Jarvik (1962) states that he has found new evidence in the anatomy of the poro- lepid Glyptolepis to confirm his original suggestions. My material Figure 10. Ectosteorhachis. Left nasal cavity. Series of sections through posterior part of the cavity, showing the postnasal wall and the associated nerve canals. THOMSON : RHIPIDISTIAN SNOUT 341 of Ectosfcorhachis sheds little light on the problem ; there is no indication of a connection between the palatinus VII and the maxillaris V as they pass through the vomer or in the space be- tween the vomer and the palato-quadrate. The canal for the ramus maxillaris V, as it passes through the vomer, gives off one, sometimes two, fine canals to the dorsal surface of the bone, but since the solum nasi is not preserved, I cannot tell whether they might represent evidence of an anasto- mosis with tlie branches of the profundus V in the nasal cavity. They may liave carried small vessels. Both the profundus and maxillary rami of the fifth cranial nerve of Ectosteorhachis have branches which, as in Eusthenop- teron, terminate close together in the most dorsal part of the anterior palatal recesses. It is not possible to tell whether or not these nerve branches anastomosed here, although Jarvik states tliat this was the case. In summary, we may conclude that in all major respects in which it is fully known, the pattern of the nervous system is essentially similar in Ectosteorhachis, Eusthenoptcron and Poro- lepis. The Vascular System of the Snout No thorough review of the vascular system of the snout of Rhipidistia may be made, since the only genus in which it is even moderately well-known is Ectosfcorhachis. Kulczycki (1960, fig. 5) attempted a reconstruction of the Avascular sy.stem of Porolcpis, but this must be treated with reservation. He did, however, find a trace of a canal which might have carried a vena cerebralis anterior — described elsewhere only in Rhizodopsis^ (Save-Soderbergh, 1936). What little Jarvik was able to restore of the vascular system of Eusihcnoptcron (1942, p. 480) seems to agree fairly Avell with the arrangement in Ectosteorhachis. COXCERNING A DIPHYLETIC ORIGIN OF THE TETRAPODS from WITHIN THE RHIPIDISTIA Reference has been made throughout this work to the distinc- tions that Jarvik (1942) lias drawn between the genera Poro- lcpis and Eusthenoptcron with respect to the detailed anatomy 1 I lirtvp SOPH thp sppciniPii stiidipd by Siive-Siidprliprtrh. Itut sim-p hp tispd thp "shatter technique" it is now impossible to learn anytliiii;; further from the specimen. 342 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY of the snout region. From his study of the snout anatomy of the Gnathostomata Jarvik drew the following conclusions : 1. That the four families of Rhipidistia may be considered to belong in two highly distinct groups: the "Porolepiformes" (comprising the families Porolepidae and Holoptychidae) and the "Osteolepiformes" (comprising the Osteolepidae and the Rhizodontidae). 2. That the two major groups of Recent Amphibia, Urodela and Anura, differ greatly from one another in their snout anat- omy and must be considered to have arisen separately from different fish ancestors. 8. That the Urodela differ from the Anura in exactly the same characteristics as the "Porolepiformes" differ from the " Osteolepif ormes, " and that the Urodela and Anura are direct descendants of the "Porolepiformes" and "Osteolepif ormes" respectively. The anatomical study of Ectosteorhachis set down above pro- vides us with a body of new evidence concerning the anatomy of the "Osteolepif ormes" which had previously been known only from study of Eusthenopteron. It is now possible to dis- cuss proposition 1 (above) in considerable (comparative) detail. Discussions of the interrelationships of the Amphibia belong elsewhere than in this paper; Parsons and Williams (1962 and 1963), Baton (1959), Schmalhausen (1959), Szarski (1962) and others have discussed the evidence for and against a fundamental separation of the Urodela and Anura. With respect to such discussion it should be noted that the ancestry of the Recent Amphibia is known only from very incomplete palaeontological evidence and discussion relies heavily on evidence from the anatomy of living forms. I shall confine myself to a considera- tion of the evidence, in the snout anatomy, for a separation of the Rhipidistia into "porolepiforms" and " osteolepif orms" with special regard to the phylogenetic implications of this pro- posed separation. In his summary of supposed distinctions between the "Poro- lepiformes" and "Osteolepif ormes" Jarvik (1942, p. 489, et seq.) enumerated some 26 points by which Porolepis (and thus the "porolepiforms") might be interpreted as differing from Eusthenopteron (and thus, typically, the "osteolepif orms"). I propose now to examine each of these points in turn, in the light of the new evidence presented in the preceding pages. Several of the 26 points overlap each other and we may group THOMSON : RIIIPIDISTIAN SNOUT 343 together first those dealinj; with the nature of the anterior palatal recesses and the "general arrangement of the ethmoid endoeranium. 1. "The internasal wall in Eiisthenopteron is narrow and forms a solid nasal septum. Tlie internasal wall in PoroUpis is broad and lodges both the ethmoidal part of the cranial cavity and the paired cavum interna.sale" (1942, p. 489)/ 2. "The divisio prenasalis communis is longer and narrower in Eusthenopteron than in Porolepis. On the latei-al parts of its lower face in Eusfhenoptvron are a pair of shallow, ventrally open prena.sal pits, situated far apart from each other; to these there is no equivalent in Porolepis. In Porolepis, on the other hand, the divisio prenasalis communis lodges the paired and comparatively deep cava prenasalia, which form the direct an- terior continuation of the cava internasalia and are situated close to each other" (1942, p. 489). 3. "Point three" states that the "shallow paired" anterior palatal recesses in Eusthenopteron contained intermaxillary glands directly equivalent to those found in the anterior part of the palate in the Anura (p. 489, cf. p. 506) and that the cava internasalia of Porolepis contained intermaxillary glands ar- ranged in the same manner as in Urodela (p. 489, cf. p. 400). 4. "The nasal cavities are fairly close to one another in Eusthenopteron, whereas they lie far apart in Porolepis" (p. 489). 26. "The anterior palatal fenestra in Eusthenopteron is comparatively small, lies entirely in front of the vomers under- neath the divisio prenasalis communis, and does not form the ventral opening of any large cavity. The anterior palatal fenestra in Porolepis is large, lies chiefly between the vomers underneath the internasal wall, and in it are seen the ventral openings of the cava internasalia and prenasalia" (p. 493). It should be noted that Jarvik distinguishes in his terminol- ogy between the apical pits and their "openings" the anterior palatal fenestrae; I prefer to use the term "anterior palatal re- cess" for the whole structure. Jarvik states that there are a pair of "prenasal" (equals "apical") pits in Eusthenopteron; but these are merely the two halves of an essentially undivided anterior palatal recess (cf. Jarvik, 1942, fig. 56). In Ectosteo- rhachis the anterior palatal recesses are definitely paired, and iln this ami the following quotations, ahlireviations and roferences to figures in the original text have been omitted. 344 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY this is the case in Megalichthys and Pandcrichthys, as well as in Porolepis and Holoptychins. It has been noted above that the cava internasalia of "porolepiforms" and the anterior palatal recesses of "osteolepiforms" are homologous structures and that their characteristic nature reflects only the nature of the teeth at the tips of the lovs^er jaw rami. Thus there is a difference in the shape of the recesses in the two groups, but, since no glandular structures are involved, comparisons with the Eecent Amphibia are not justified. It has been noted also that the presence or absence of an ethmoid division of the cranial cavity — the pars ethmoidalis cranialis — is of random occurrence in the families of Rhipidistia and does not characterise any particular group. As has been pointed out in a previous paper (Thomson, 1962), the internasal wall in the "osteolepiforms" may be broad or narrow and there is no evidence to support the theory that the presence or absence of the cava internasalia or the pars eth- moidalis cranialis is correlated simply with the relative width of the internasal wall or the relative size of the nasal sacs (cf. Schmalhausen, 1959; Romer, 1962; Szarski, 1962). 5. "The lamina nariochoanalis is in EustJienoptcron formed by the lateral nasal wall, in Porolepis both by the lateral nasal wall and an adjacent part of the solum nasi" (1942, p. 490). The solum nasi is not preserved in Ectosteorhachis. But whereas in the postehoanal region the lateral nasal wall curves slightly underneath the nasal cavity (Fig. 9, A, B), in the choanal region this slight ledge is not present (Fig. 8, A, B), and this may indicate that the lamina nariochoanalis was formed only by the lateral nasal wall. 6. " Eusthenopfcron has no equivalent to Seydel's palatal process in Porolepis" (p. 490). Jarvik's identification of a small backwardly directed process on the anterolateral margin of the choanal aperture in the solum nasi of Porolepis as an homologue of the Seydel's palatal process of Urodela has been criticized by Kulczycki (1960) who has pointed out that if the subnarinal crest of Porolepis (see above) is homologised with the crista rostrolateralis of Urodela, then the small choanal process which lies "along its prolongation" is in a different position from that of Seydel's palatal process in urodeles. The process was not seen in Ectosteorhachis. 7. "The fenestra endonarina anterior and the fenestra endo- choanalis are comparatively large in Eusthcnoptcron" (p. 490). THOMSON: IMIIIMDISTIAN SNOUT 345 This does not seem a character of great phylogeiietic impor- tance. Ill Ectosteorhachis the fenestra endonarina is relatively slightly smaller than that of Eusthenopteron; the fenestra endo- choanalLs is of the same relative size. 8. "'The fenestra endonarina posterior in Eu.sth()ioj>lcron is an opening in the postnasal wall leading backwards to the anterior ventro-lateral part of the orbit, and is separated ven- trally b}^ an endoskeletal bridge from the fenestra endochoanalLs ; in Porolcpia it lies in the lateral nasal wall and is continuous ventrally w^ith the fenestra endochoanalis" (p. 490). The posteroventral fenestra of Ectosteorhachis corresponds to the opening in the postnasal wall of Eusthenopteron which Jar- vik has homologised with the posterior external naris of Poro- lepis. It is difficult to tell whether Jarvik's proposed homology is justified or not ; it seems to me that this fenestra may pos- sibly have been one of the main openings through which the venous vessels left the nasal cavity and it is not impossible that nerve branches pa.ssed through it. Jarvik assumed that this fen- estra connected by means of a duct (the forerunner of the iiaso- lachrymal duct [1942, p. 537]) with the orbit but since the soft anatomy is not preserved there is no way of checking this hypothesis. It is interesting to note that Vorobjeva (1960a) has described the osteolepid Panderichthys as having two external nares, the posterior of which is confluent with the endochoanal aperture. If this observation is substantiated this genus may thus represent some sort of link between the "Porolepiformes" and the "Osteo- lepiformes" wath respect to this important character. 14. Point 14 refers again to the difference in the relative positions of the posterior external naris in Porolepis and its "homologue" in Eusthenopteron, and mentions again tlic jios- sible homology of this structure in Eusthenopteron with the tetrapod nasolachrymal duct. This has been dealt with above. 9. "No canal corresponding to the nasobasal canal in Eusthen- opteron exists in Porolepis. On the other hand the orbitorostral passage and the canal c.vl in Porolepis have no equivalents in Eusthenopteron" (p. 490). The nasobasal canal carried the terminal branch of the ramus medial is narium of the profundus V nerve through the anterior nasal wall into the anterior palatal recess in Eusthenopteron; a similar canal is present in Ectosteorhachis. As mentioned above, Kulczycki (1960) has noted a canal in Porolepis also 346 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY which may correspond to this canal. The orbitorostral passage was not found in Ectosteorhachis. Knlezycki could not find this passage in his material of Poro- lepis. The "canal c.vl" is .something of an enigma; it lies in the lateral part of the postnasal wall of Porolepis and was supposed by Jarvik to carry a lateral branch of the profundus V nerve. However, it could very possibly have contained a blood vessel, particularly a vein, draining the nasal cavity. It is not present in Ectosteorhachis. 10. "In Eusthenoptcron there is a single nerve-canal leading upwards from the nasal cavity to the dorsal face of the ethmoidal region ; in Porolepis a great many nerve-canals ascend from the nasal cavity to the dorsal face of the ethmoidal region, piercing the dorsal part of the medial nasal wall, the adjacent part of the prenasal wall, and the medial parts of the tectum nasi" (p. 490). Point 19 refers to the same subject: "The n. profundus in Eusthenoptcron was comparatively weakly developed. . . . The n. profundus in Porolepis was strongly developed. ... In the nasal cavity the medial nasal branch divided into numerous dorsal branches" (p. 491-492). As has been noted in the previous discussion, the ramus pro- fundus of the fifth cranial nerve seems to be developed in approximately the same manner in Porolepis, Eusthenopteron and Ectosteorhachis. The canals passing through the dorsal wall of the nasal capsule of Porolepis seem to pertain to the ophthal- micus superfieialis VII nerve rather than to the profundus V. Thus, whereas the rami profundi of "Porolepiformes" and " Osteolepif ormes " are similar, there may be a difference in the path of the ophthalmicus superfieialis nerve — within the nasal cavity in Porolepis, and external to the nasal cavity in Eusthen- opteron and Ectosteorhachis. 11. "The postnasal wall is pierced in Eusthenopteron by a single and not particularly wide profundus canal; in Porolepis by a wide medial and one or several narrower lateral profundus canals" (p. 490). We have noted above that there may be some variation in the number of canals through which the profundus nerve enters the nasal cavity. 12. 13, 15. Points twelve and thirteen deal with the apparent subdivision of the chamber of the nasal capsule into recesses by TIIOMSOX : IMIIIMDISTIAX SXOl'T 347 tiic presence of various ridyes and crest.s on the medial surfaces of the walls. I'oiiit 15 may also be discussed here, since it states that "The large diflferences in the nasal cavity show that there must liave been considerable differences [between Eusthenopteron and Porolepis] in the develoj)nient of ihe nasal sac" (pp. 490- 491). The subject of the ridges and crests of the nasal capsule has been reviewed above and we have seen that the conditions in Porolepis, Eustlienopteron and Evtosteorhachis may possibly be related to each other. The processus intermedius (or its homo- logue) may be present in Porolepis as well as in Eusthenopteron and the subnarinal ridge seems to be present, slightly modified, in all three genera. It is not possible to decide with any degree of certainty whether or not the apparent morphological subdivisions of the nasal capsule represent any functional anatomical features of the nasal sac. For example, the ventromedial recess of Eusthe- nopteron corresponds exactly to that of Ectosteorhachis, but whether this recess of the nasal cavity contained a diverticulum of the nasal sac, and whether such a diverticulum, if present, would have contained Jacobson's organ (cf. Jarvik, 1942, pp. 483, 536) cannot be decided from the fossils alone. And while answers to such questions may be formulated from comparisons with the Recent Amphibia, the objective purpose of the study would then be defeated. 16. "The forebrain in Eusthenopttron was of approximately the same breadth as the diencephalon ; . . . The bulbi olf actorii in Eusthenopteron lay close to one another immediately in front of the hemispheres, whereas in Porolepis they were situated far apart at the lateral sides of the hemispheres" (p. 491). This apparent distinction arises from interpretation of the pars ethmoidalis cranialis of Porolepis as having contained the "hemispheres of the forebrain." In fact, available evidence now indicates that the pars ethmoidalis cranialis, which is of random occurrence throughout the Rhipidistia, did not contain Q-wy part of the brain anatomy, and that the brain of Porolepis was probably not greatly different in overall configuration from that of Eusthenopteron. 17. "The lateral parts of the snout were in Eusthenopteron supplied mainly by the r. maxillaris V, in Porolepis mainly by the n. profundus" (p. 491). There is no doubt that in many adult Urodela, such as 348 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY Salamandra, which Jarvik took as his example for the group (Francis, 1934), the maxillaris V terminates in the orbit, as Jarvik has suggested is the ease in Porolepis. But in many aquatic Urodela and in the larva of Salamandra, in which the lateral line system is retained, the lateral line nerve — ramus buccalis lateralis VII — is bound into a "truncus infraorbitalis" with the maxillaris V nerve. This compound trunk passes an- teriorly right into the snout region, carrying the maxillaris V further anteriorly than in the terrestrial Urodela. It has often been supposed that the Khipidistia resembled, in their anatomy, the larvae of Amphibia more strongly than they resembled adult forms. If, therefore, any traces of the ramus buccalis lateralis VII nerve are to be found in the porolepid Rhipidistia then the po.ssibility cannot be excluded that the ramus maxillaris V was also present. 18. "In Eusthenopteron the r. buccalis lateralis passes for- wards in the pons nariochoanalis laterally to the choana, giving off branches to the neuromasts of the anterior parts of the infra- orbital sensory canal. It terminated far anteriorly near the very tip of the snout. In Porolepis it presumably broke up into several terminal branches while still in the orbit. One of these terminal branches, which supplied the foremost neuromasts of the infraorbital sensory canal, went forwards through the orbitorostral passage medially to the choana" (p. 491, cf. Jarvik, 1962). Kulczycki (1960) has queried Jarvik 's restoration of the orbitorostral passage in Porolepis. In Ectosteorhachis the nerve may possibly have passed through the dermal bones of tlie snout rather than between these bones and the nasal capsule as is the case in Eusthenopteron. Knowledge of the exact ar- rangement of the ramus buccalis lateralis in Rhipidistia is far from satisfactory. 20. "The r. palatinus VII in Eusthenopteron pierced the anterolateral part of the vomer and during this part of its course it broke up into three branches ... In Porolepis the r. palatinus VII probably did not divide during its passage through the vomer . . ." (p. 492). The ramus palatinus VII did not branch during its passage through the vomer in Ectosteorhachis. In this genus, as in Porolepis, the nerve ran through the medial part of the vomer. 21. Point 21 deals with the fact that Jarvik found traces of fusion between the tip of the palato-quadrate and the socket THOMSON : KMIIl'IDISTIAX SNOTT 349 for it ill the (MKlocraiiiuiii, in PJxstln iioph rtjii but not in I'oro- lepis (p. 492). In Ectosteorhacliis, as noted by Konier (H'.'^, p. 22). the notch for the reception of the palato-quadrate is not lined by periosteal lione, and thus in this respect Ectostroihachis agrees with Ensthenopteron. 22. Point 22 states that the pineal opening, between the "frontal" bones (parietal bones) is characteristically present in "Ensthenopteron and other Osteolepiformes" but is absent in Porolepiformes. In the family Osteolepidae the i)ineai openinji' is present in Osteolepis and other Devonian forms, but absent in Megalich- thys and Ectosteorhachis. 23. "The vomers in Ensthenopteron meet anteriorly in a median suture but their long posterior processes diverge and are separated from one another by the parasphenoid. Each vomer is provided with a descending tooth-bearing lamina. The vomers in Porolepis lie mainly in front of the parasphenoid. Their pos- terior parts are close to one another, but further anteriorly they diverge strongly. They have neither a posterior process nor a descending tooth-bearing lamina" (p. 492). The vomers of EctosteorhacJris, Megalichthys, (ihi}>t<)pi>)nns, and probably also Osteolepis and Thnrshis (all osteolepids) lack the posterior process of Ensthenopteron (Th( mson, 1964 ) ; the vomers in each of these genera lie anterior to the parasphenoid. It seems quite possible, although not all genera are yet well enough known, that the posterior process of the vomer is a special characteristic of the Rhizodontidae. The vomers of Ectosteorhaehis but not Me(jalichthys have an anterior tooth-bearing lamina comparable to that of Ensthenop- teron. Discussion of the vomers is closely tied up with the next subject — the nature of the parasphenoid. 24. "The parasphenoid in Ensthenopteron is narrow and goes forward underneath the ethmoi:^ Figure 9. Nape scales just lateral to the dorsal midline in two forms of Anolis marmoratus: 1. kahouannensis, type (MCZ 70791); 2. setosus, type (MCZ 70813). Variation: The extent of blue wash on the heads of males varies from the condition described for the holotype to virtually absent. One specimen (MC'Z 70792) darkened in blotches when changing- to the dark phase; this was only vaguely reminiscent of the condition visible in setosus. The adult female is almost completely without markings. There i.s no mottling, stippling, or streaking, though occasional seg- ments of the ladder middorsal pattern characteristic of the young female may be retained in sexually mature individuals. The basic color is pea-green, and the belly is bright yellow. Distribution: This anole is confined to Ilet-a-Kahoiianne. Paratypes: MCZ 70792-803, same data as the type. Discussion: Assignment to subspecific rank under mnrmoratus is, in this case, an arbitrary action supported only by direct evidence, in the Ilet-a-Fajou population, that a tendency towards large scale size can occur in small, isolated marmoratus popula- tions. Because the Ilet-a-Fajou population does demon.strate that enlarged scale size is within tli(> potential evolutionary role of 384 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY marmoratus, it is at least possible to regard kahouannetisis as a subspecies of marmoraius with respect to this character. It is, however, disquieting to note that kaJiouannensis is 100 per cent distinct on the basis of coloration in life, quite apart from the scale size discrepancy. In the final analysis, there is no conclusive argument for the inclusion of this form within the marmoratus species; there is, nevertheless, a tenable argu- ment that it should be included, since all of the mainland Guadeloupeen forms are 100 per cent distinct on the basis of coloration in life if intergrades are not considered. A. m. ha- houannensis has no possibility of producing an intermediate population with the mainland forms, but I have, nevertheless, accepted it as a subspecies of marmoratus because such a judg- ment is tenable and because in my own opinion kaJiouannensis is not more distantly related to setosus than setosus is to those mainland forms with which it intergrades directly. My opinion is based on a general impression of these taxa both in life and after preservation ; it is thus the sort of opinion that can neither be proven nor disproven on the basis of present information. Authors who wish to regard this form as a species distinct from marmoratus can find ample justification for doing so. However, the Kahouanne Island anole resembles setosus with regard to the convexity and spinosity of the dorsal scales, and fits A. marmoratus generally with regard to the prenasal and the ventral keeling. Anolis MARMORATUS sPECiosus Garmaii Anolis speciosus Garman, 1887, Bull. Essex Inst., 19:45. Cotypes: MCZ 6172, 70947-50. Lectotype: Here designated as MCZ 6172, collected by Richard- son, March, 1886. Type locality: "Marie Galante" (in error) ; here revised to Pointe-a-Pitre, Grande Terre. Diag7iosis: Dorsals in the standard distance 32 to 50 (average 40); 20 to 26 (average 23) subdigital lamellae; adult male green, without dorsal markings ; venter brightly washed with yellow ; orbital area sky-blue ; throat fan sulfur-yellow with greenish scales. Adult female olive with ladder or striped mid- dorsal pattern. Description: MCZ 70961, an adult male from Pointe-a-Pitre, in life was bright green over the entirely unmarked dorsum. LAZELL : GUADELOUP^EN ANGLES 385 The venter was entirely washed with bright yellow, producing a deep yellow-green zone along the sides. The orbital skin was skA'-blue, and sharply set oflP from the green color of the rest of the head. The throat fan was sulfur-yellow with green-grey scales. This male had several clusters of yellow scales scattered on the sides of the neck, reminiscent of some sctosiis males. The scales of the dorsum are not spinose (i.e. never taller than broad), and closely resemble the dorsal scales of anoles (exclud- ing setosus) from La Guadeloupe. Color change involved merely a darkening of the ground color to slatey-green, accompanied by greying of the orbital skin. This specimen, the largest exam- ined, measured 71 mm in snout-vent length. The adult female is olive-green, has a striped or ladder mid- dorsal pattern, and lacks other distinctive markings including a flank stripe. Variation: This form is remarkably constant in color charac- ters. As with setosus, the presence of yellow scale clusters on the neck is occasional in old adult males and not relevant to the taxon. Specimens from Ilet-a-Cochons and the south coast of Grande Terre sometimes show a more gradual blending of the blue coloration of the orbital region with the green of the head than do specimens from the more northern portions of the range. There is, however, never a dark stripe through the eye, as in setosus. Distribution : This form occurs throughout SW Grande Terre (i.e., the wetter area of this island), on the "waist" between Grande Terre and La Guadeloupe, and on Ilet-a-Cochons (some- times called, uncomplimentarily enough, Ilet-a-Gouvernement). Specimens examined: MCZ 6172, "Marie Galante," Lectotype (Richardson coll.) ; MCZ 70947-50, "Marie Galante," Paralecto- types (Richardson coll.); MCZ 70913-24, Abymes; MCZ 70925- 34, Gosier; MCZ 70935-46, Ste. Anne; MCZ 70951-60, Baie Mahault; MCZ 70961-77, Pointe-a-Pitre ; MCZ 70978-87, llet-a- Cochons, ou Gouvernement. Discussion: The locality of this form given by Garman (pre- sumably fide Richardson) in the original descrii)tion is incorrect. The five males in the type series (MCZ 6172, 70947-50) fit quite precisely with the form from SW Grande Terre on squamation characters and are powder-blue from long preservation. They completely lack markings such as the faint flank stripe and brown head (which does not turn blue in preservative) that characterize the NE Grande Terre population, the only other form that these long-preserved specimens might conceivably be 386 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY confused with. Richardson demonstrably collected in both De.si- rade and Marie Galante. It would have been remarkable indeed if he had failed to stop at the large and busy port of Pointe-a- Pitre while in this area. To add to the evidence against the "Marie Galante" locality is the fact that no specimen resembling speciosus has ever been collected there since, whereas the Marie Galante anole, ferreus, is common indeed — though its original type locality was cited as "Guadeloupe." Intergradation with nominate marmorafus, oUiaceus, and seto- sus ha.s been discussed under those forms, respectively. Inter- gradation with the dry country form of NE Grande Terre, inornatus, occurs along a line through Morne-a-L'Eau (MCZ 70885-94), Chateau Gaillard (MCZ 70895-902), and St. Francois (MCZ 70903-12). Anolis marmoratus inornatus^ subsp. nov. Holotype: MCZ 71036, collected 13 August 1961, by J. D. Lazell, Jr. Type locality: Anse Bertrand, Grande Terre. Diagnosis: Dorsals in the standard distance 38 to 53 (average 47) ; 20 to 26 (average 25) subdigital lamellae; adult male pale grey -green on trunk, rich brown on head ; orbital area brown ; belly pale lime-green; throat fan yellow with white to cream- colored scales ; flank stripe indicated. Adult female pale grey- brown with striped middorsal pattern and flank stripe. Description of holotype: This adult male was pale green with a bluish tinge on the posterior body and tail base. The head was Avarm brown ; the orbital skin golden brown. The brown of the head graded gradually into the green of the dorsum. There were faint, grey-brown vermiculations on the nape. The belly was pale, dirty green posteriorly, becoming lime-green in the chest region. The throat fan was dull yellow with white scales. A flank stripe, paler grey-green than the dorsal ground color, extended from the shoulder to the hind limb insertion. There were faint indications of darker grey-brown transverse markings across the dorsum. The slight color change involved a general trend towards becoming darker and browner. This speci- men, the largest examined, measured 75 mm snout to vent. Variation: This form is rather variable. Some specimens lack all signs of neck vermiculations or transverse markings. The 1 hiornatun, Latin, for "unadorned." LAZELL : GrADETiOrPKEN' ANOLES 387 amount of green varies from tlic condition described for the li()loty])e to one in whicli it is virtually restricted to tlie posterior belly and rump regions. In most specimens the throat fan ap- pears to have a paler yellow border and a brighter yellow center, and the scales of the fan are often closer to cream-color than white. The variation is individual and does not correspond to different localities within the range of the form. The adult female is pale tan to ash-grey on the dorsum, and always brownish on the head. The striped middorsal pattern is not bold but is always noticeable. A definite flank stripe is indicated in the thoracic region. Distribiitton: This form occurs throughout northern (4rande Terre and extends southeastward along the northeast coast of that island towards, but not to, Pointe-des-Chateaux. Parotjjpes: MCZ 71037-42, .same data as the type: :\1C'Z 61082- 92, Mouie (Proctor coll.) : MCZ 71014-19, Moule ; MCZ 71020-25, Petite Canal: MCZ 71026-35, Port Louis; MCZ 71043-48, Cam- peche; MCZ 71049-57, town of Ste. Marguerite. Discusfiion: Intergradation with spcciosna has been discussed under that form. The population on the Pointe-des-Chateaux peninsula requires especial consideration. The males from this area show definite vermiculation on the nape, and usually a few bold, dark spots at least in the dark phase. There is a noticeable yellow wash along the sides and the orbital skin has a distinctly orangish tone in some specimens. In keeping with the norm of intergrade populations in the archipelago, the.se anoles are very variable : some closely resemble inornatus in important respects, others closely approach the anole found on the adjacent island of La Desirade. Therefore, MCZ 71058-67, from Pointe-des-Chateaux, are regarded as a sample of an inter- mediate population between inornatus and the following form : Anolis marmoratus desiradei subsp. nov. Holotype: MCZ 71068, collected 14 September 1961. by J. D. Lazell, Jr. Type locality: Grande Anse, La Desirade. Diagnosis: Dorsals in the standard distance 32 to 50 (average 40) ; 22 to 28 (average 25) subdigital lamellae; adult male pale greenish with yellow wash on sides and yellow belly ; dorsal surfaces extensively vermiculated wath darker grey -brown ; throat fan yellow with white to cream-colored scales; orbital area bright 388 BULLETIN : MUSEUM OP COMPARATIVE ZOOLOGY rust-red ; chin yellow with bold blue-grey streaking. Adult fe- male grey-greenish with grey head and yellow belly; middorsal pattern obsolete. Description of holofype: This adult male was pale grey-green boldly vermiculated with dark grey-brown all over the dorsal surfaces of the trunk and legs. The lateral surfaces were washed with yellow, and the belly was bright yellow. A lack of vermicu- lation along the side indicated a vague flank stripe. The chin was yellow and blue-grey bars ran from the anterior base of the throat fan to the infralabials. The head was dull brown to grey-brown, and the bright rust-red of the orbital skin stood out in bold contrast. The throat fan was yellow with cream- colored scales. Color change involved general darkening and increased brownness ; the vermiculations became especially bold in the dark phase. The holotype, the largest specimen examined, measured 80 mm snout to vent. Variation: There is a definite cline in extent of yellow on the sides and in the ground color, increasing as one proceeds east- ward along La Desirade. Some specimens from all over the island show small orangish patches on the nape and anterior body; this is by no means constant and not characteristic of the taxon. The adult female is distinctly grey on the head and becomes greener posteriorly. There is no indication of vermiculation. The belly is distinctly yellow. Young specimens show a vague striped middorsal pattern, but those apparently mature females were somber grey middorsally, producing the pattern I have called obsolete. Distribution: This form is confined to the island of La Desi- rade. Paratxjpes: MCZ 57285-96, "Desirade Id." (Richardson coll.) ; MCZ 62210-1, Ravine la Riviere (Proctor coll.); MCZ 62212, Le Calvaire (Proctor coll.) ; MCZ 62213-17, Grande Anse (Proc- tor coll.) ; MCZ 71069-77, Grande Anse; MCZ 71078-87, Pointe- des-Colibris; MCZ 71088-100, Le Souffleur; MCZ 71101-12, Pointe Double. Discussion: The intermediate population between inornatiis and desiradei has been discussed under that form. It need only be pointed out here that this population, while not one of "intergrades" as such, precludes the possibility of recognizing desiradei as a species distinct from marmoratus: on Pointe-des- Chateaux, Grande Terre, some anoles that are unequivocally marmoratus show desiradei characteristics. LAZELL : GUADELOUPEEN ANGLES 389 lj(':h tlic "satellite" islands of the ardiipchiiio. Tlic first pojjulation of this series is : AxoLis MAR:\iOKATrs ciiRVsops^ sn])sp. IIOV. Ilolohjpi : MCZ 7064!), collcc-tcd 4 September l!)(il, hy J. 1). Lazell, Jr. Ti)p( local ih/: Terre de Hant, T^es Ties de la Petite Teri-e. Diagnosis: Dorsals in the standard distance 30 to 42 (average 36) ; 22 to 28 (average 25) subdigital lamellae; adult male som- ber green-grey with bright yellow suffusion on the sides and bright yellow belly; vermieulations present on the anterior trunk and nape, at least, and dark dotting usually present on remaining dorsal surfaces ; orbital area red-gold ; chin entirely blue-grey; throat fan yelloAv with pale yellow scales. Adult female grey with yellow belly, an ob.scure striped middorsal pattern, and a brief flank stripe. Description of holotype: This adult male was grey-green, becoming greener posteriorly and virtually grey (or grey-brown) on the head. The yellow of the venter extended as a bright suffusion over the lateral trunk. The vermieulations tended to break up into small speckles on the i)osterior body and hind limbs; no notable lack of vermiculation distinguished a flank stripe region. The chin was entirely blue-grey, and the skin of the orbital area was red-gold. Color change was merely to slightly darker and browner. The holotype, the largest specimen examined, measured 73 mm snout to vent. Variation: The extent of vermiculation and its break-up into speckling is rather variable, but specimens always show vermicu- lation as such at least on the nape and anterior trunk. Some specimens showed a vague indication of the vermiculation-free flank stripe area, though this region is usually heavily invaded with yellow. The color of the orbital skin and the uniformity of the blue-grey chin are constant features. The adult female is distinctly duller and greyer tlian the average desiradei female and retains the striped middorsal pattern. The contrast between the grey of the head and the green-grey of the dorsum is not marked, though the belly is bright yellow. A short flank stripe is present. Distribution: Terre de Haut and Terre de Bas, Les lies de la Petite Terre. 1 Chrysos, Latiu, for "^olil," [ilits oijs, Gri'ok, tor •'iippeariiiu'e." 390 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY Paratypes: MCZ 70656-65, same data as the type; MCZ 70650-5, Trou Canard, Terre de Bas, Les lies de la Petite Terre. Discussion: The Petite Terre anole agrees with desiradei in possessing vermiculations, though they are reduced from the condition in that form; it agrees, on the other hand, with ferreus in having a uniform blue-grey chin, though the blue- grey does not extend onto the throat fan, as it usually does in ferreus. The orbital skin color, though entirely distinctive, is what one would expect of a mixture between the rust-red of desiradei and the dull yellow of ferreus. The extent of yellow on the lateral surfaces is likewise intermediate between these two forms. Dorsal scale size shows a marked overlap with desiradei, on the one hand, and ferreus, on the other. Some adult males have the neural spines of the caudal vertebrae dis- tinctly more elongate than in any desiradei and as elongate as in some ferreus. Therefore, in every respect except maximum snout-vent length (in the sample available), chrijsops is morpho- logically intermediate between two extremes : desiradei and ferreus. In contrast with the Ilet-a-Fajou population, which is also an isolated morphological intermediate, cJirysops is entirely dis- tinctive in its own right ; there is no intergrade population with which chrysops individuals could be confused, and there are diagnostic characteristics by which chrysops may be un- equivocally distinguished. For these reasons A. m. chrysops is granted nomenclatural rank. Because it is an intermediate population between A. m. desiradei and ferreus of Marie Galante and because it is geographically intermediate as well, it connects the Marie Galante anole with the remainder of the marmoratns series, and ferreus must therefore be regarded not as a distinct species but as : Anolis marmoratus ferreus (Cope) XipJiosunts ferreus Cope, 1864, Proc. Acad. Nat. Sci. Philadelphia, 168. Type: BMNH 1946. 8.5.59., no collector, no date. Anolis asper Garman, 1887, Proc. Essex Inst., 19: 31. Syntypes: MCZ 6162. (Type locality Marie Galante.) Type locality: "Guadeloupe" (in error) ; here revised to Morne Constant, Marie Galante. Diagnosis: Dorsals in the standard distance 22 to 38 (average 28); 25 to 30 (average 28) subdigital lamelhie; adult male somber grey-brown becoming greener posteriori}- ; dorsum sprin- kled with dark dots seldom coalescing to form short vermicula- tions ; suffusions, often forming blotches, of yellow laterally ; LAZELL: GUADELOUPfiEN ANGLES 391 orbital area dull yellow; uiiifoiiii l)lue-f oculaftts on Dominica. The anoles of the eastern Caribbean (Sauria, Iguanidae). Part Y. Bull. Mus. Comp. Zool., 127(9) : 466-475. Simpson, G. G. 1961. Principles of Animal Taxonomy. Columbia Univ. Press, New York, xii -f 247 pp. Underwood, G. 1959. Revisionary notes. The anoles of the eastern Caribbean (Sauria, Iguanidae). Part III. Bull. INIus. Comp. Zool., 121(5): 191-226. Underwood, G. and E. E. Williams 1959. The anoline lizards of .laiiiaica. Bull. Inst. Jamaica, Sci. Ser., 9: 1-48. LAZELL : GUADELOUPEEN ANGLES 401 TABLE 1 Home color characteristics of adult males of the twelve subspecies of Anolis inunuoratus in the (iuadeloupeen archipelago. girafus brown to green + blue light reticulations setting off dark areas setosus green + blue dark, temporary, transverse bars l-ahouannrnsis chartreuse (= bright yellow-green) speciosus green -|- blue none iiwrnafit/^ dull greenish faint trans- verse bars; flank stripe vellow desiradci chrysops pale grey-green verniiculations yellow white pale grey-green vermiculations reduced ferrens grey-brown + green flecking terraealtae grey-brown -\- green yellow blotches caryae pale green fine, pale vermiculations Sulispecies Ground Color Markings Tliroat Fan Throat Fan Orbital Skin Scales A I ea inarmoratus green -|- blue orange marbling anteriorly orange-yellow yellow marbled orange alUacriis green light bordered, dark spots dull orange green brown-green lids white yellow white brown yellow greenish dark green yellow yellow greenish yellow greenish sky blue white brown red yellow yellow red-gold yellow yellow dull yellow ± grey ± grey yellow yellow dull-yellow vellow yellow cream -colored Bulletin of the Museum of Comparative Zoology HARVARD UNIVERSITY Vol. 131, No. 12 ANOLIS EQUESTRIS IN ORIENTE PROVINCE, CUBA By Albert Schwartz With One Plate CAMBRIDGE, MASS., U.S.A. PRINTED FOR THE MUSEUM September 15, 1964 Publications Issued by or in Connection WITH THE MUSEUM OF COMPARATIVE ZOOLOGY HARVARD UNIVERSITY Bulletin (octavo) 1863 — The current volume is Vol. 131 . Breviora (octavo) 1952 — No. 207 is current. Memoirs (quarto) 1864-1938 — Publication terminated with Vol. 55. Johnsonia (quarto) 1941 — A publication of the Department of Mollusks. Vol. 4, no. 41 is current. Occasional Papers of the Department of Mollusks (octavo) 1945 — Vol. 2, no. 28 is current. Proceedings of the New England Zoological Club (octavo) 1899-1948 — Published in connection with the Museum. Publication terminated with Vol. 24. The continuing publications are issued at irregular intervals in num- bers which may be purchased separately. Prices and lists may be obtained from the Publications Office of the Museum of Comparative Zoology, Cambridge 38, Massachusetts. Peters' Check-List of Birds of the World. Volumes 1, 4 and 6 are out of print ; volumes 2, 3, 5, 7, 9, 10 and 15 are currently available. Phylogeny and Evolution of Crustacea. Proceedings of a confer- ence held at Cambridge, Mass., March 6-8, 1962. H. B. Whittington and W. D. I. Rolfe, editors. Cambridge, Mass., 192 pp., 80 figs., 1963. Cloth bound, $6.75. Fishes of the Gulf of Maine, by Henry B. Bigelow and William C. Schroeder. Washington, viii - 577 pp., 1953. Photo-offset reprint, $6.50. Publications of the Boston Society of Natural History The remaining stock of the scientific periodicals of the Boston Society of Natural History has been transferred to the Museum of Comparative Zoology for distribution. Prices for individual numbers may bo had upon request. Bulletin of the Museum of Comparative Zoology H A R V A R I) U N I V E R S I T Y Vol. 131, Xo. 12 ANOLLs EQIESTUIS IX OKIEXTE PKOVIXCE, Cl'lJA By Albert Schwartz With One Plate CAMBRIDGE, MASS., U.S.A. PRINTED FOR THE MUSEUM September, 1964 Bull. Mus. Comp. Zool., Harvard Univ., 131 (IJ) : 403-428, Sept., 1964 No. 12 — Anolis cqucstns in ()>•{( ntc I'rorincc, Cuba By Albert Schw.xhtz ' IXTHODIC'TIOX In 1!)58, [ reviewed the suhspeeies of the C'uban <;iaiil uiiole. Anolis equestris. At that time, the only .specimens from Orients, the ea.sternmost Cuban provinee, were .sixteen individuals, all in rather poor condition and most of which had been in j)i'eservation for some time. Also, of these sixteen, nine were from the north- western coast of Oriente and represented the subspecies thomasi, thus leaving only seven lizards from the remainder of the prov- ince. Since tiiat time, 1 have collected a series of these anoles in Oriente, under National Science Foundation grant (J-()2r)2, in the summers of 1959 and I960; in addition, in the belief that Oriente equestris could best be treated as a unit and on the basis of all available material, Dr. Ernest E. Williams has invited me to study certain .specimens he was intending to describe, as well as certain comparative material obtained in Cuba under XSF Grant G-16066 or borrowed by him from the Hamburg Museum. The gathering together of all this material makes it possible to clarify the Oriente picture a bit more satisfactorily, although all questions are by no means answered. I wish to thank Ronald F. Klinikowski, David C. Leber, James D. Smallwood, and Barton L. Smith for th(Mi- assistance in the field. Mr. Klinikowski has also made the illustrations for the present paper. In addition to specimens borrowed from the Museum of Comparative Zoology (MCZ), the Hamburg Museum (HM), and the American Museum of Natural History (AMNH), for which I wish to thank Dr. Ernest AVilliams, Dr. Werner Ladiges, Charles M. Bogert, and Dr. Richard G. Zweifel, I have examined material from the Carnegie ^Museum (CM) under the care of Neil D. Richmond, and the Museo y Biblioteca de Zoologia de la Habana (]\IBZH) which was formerly under the curatorship of ]\Iiguel L. Jaume Garcia; specimens from the United States National Museum (IJSNM) are currently not avail- able, but I have previously taken scale counts and measurements on the pertinent specimens in that institution, and the loans were made at that time by Dr. Doris M. Cochran. All these curators deserve my sincere thanks for their cooperation. 1 Present address: lO.OOO S.W, s4tli Street, Miiiiiii 4:!. Florida. 406 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY SYSTEMATICS In my previous paper I referred all Oriente Anolis cquesfris (except those from the northwestern coastal region of Banes and Gibara) to the subspecies nohlei; the Banes and Gibara material was clearly referable to the more western race thomasi. At the same time, I mentioned (1958 :6) a bizarrely patterned individual from the Rio Yateras, which lies to the east of the Bahia de Guantanamo, and commented that "additional specimens from this area would be instructive." One other fact is worthy of mention: when Barbour and Shreve (1935:250-51) described A. e. 7Wblci, they had only three specimens, two of which were juveniles. The type, an adult male, is from the Sierra de Nipe, a poorly restricted locality ; of the two juvenile paratypes, one is from Santiago de Cuba and the other from near Guantanamo. Although immature, the Santiago de Cuba .specimen is sufficiently grown to demonstrate that it is not assignable to nohlei but rather to the race which occurs between the Bahia de Santiago and the Bahia de Guantanamo. The Guantanamo juvenile is so young that it lacks any adult pattern and has only the uniform dorsal ground color (presently brown, but emerald green in life) with a series of four paler dorsal crosstands; this coloration is gener- ally that of juveniles of most races of A. equestris. A. c. thomasi is the giant anole of the northern Oriente coast from the Camagiiey-Oriente line as far east as Banes. Remark- ably, a young specimen (snout-vent length 113 mm) from Cabo Cruz (AMNH 83632) is likewise clearly of this .same race (see Figure 1). There are no specimens of A. equestris from the interior of western Oriente, but on the basis of the Cabo Cruz and northern coastal records, the implication is clearly that A. e. thomasi occupies more or less the western third of Oriente. Considering the subspecific differentiation in A. equestris in the remainder of the province, this widespread distribution of A. e. thom^asi is rather surprising. Considering, however, the relative uniformity of the western third of Oriente in contrast to the great ecological diversity of the balance of the province, the widespread occurrence of A. e. thomasi is more or less to be expected. This more western subspecies occupies the Camagiiey- Tunas-Holguin subregion and the Cauto-Alto Cedro Plain (]\Iar- rero, 1951 :550 et seq., 636 et seq.). The former of these physio- graphic regions is that area occujned by thomasi in the province of Camagiiey, and the latter region covers most of central western Oriente and extends from north of the Sierra Maestra south almost to Cabo Cruz. SCHWARTZ : AXOLIS EQUESTRIS IN ORIENTE 407 The eastern two-thirds of Oriente, as well as the entire .southern coast, is mountainous ; the Sierra Maestra extends from the vicinity of Pilon on the west (near Cabo Cruz) to the Bahia de Santiago on the east ; between this bay and the Bahia de Guan- tanamo lies the isolated but nonetheless related Sierra de Gran Piedra. The Sierra Maestra-Gran Piedra massif is bounded on the north by the valley of the Eio Cauto. The remainder of the province is composed of one grand mountainous mass, variously subdivided and of varying elevations ; in .some areas precise names have been associated with especiallj^ prominent ranges ; the Sierra de Nipe and the Sierra de Cristal are two of these, south of the Bahia de Nipe and to the south between the cities of Mayari and Sagua de Tanamo, respectively. The eastern quarter of the province is occupied by the extremely rugged and dissected mountain mass which is customarily named the Cuchillas de Toa. The southern coast lies in the rain shadow of the Sierra Maestra, Sierra de Gran Piedra, and the Sierra de Purial (a subdivision of the Cuchillas de Toa) ; this coastal strip is ex- tremely hot and xeric, with vegetation typical of such areas in the tropics — cacti, acacias, and many shrubby plants. The north coast, north of the Cuchillas de Toa, is luxuriant, and in many places the rain forest descends almost to the coastal beaches themselves. From the above brief discussion it should be obvious that much of Oriente is varied both climatically and physio- graphically; against such a setting it is not likely that A. equcsfris, which is tolerant of a wide variety of ecological con- ditions, would remain undifferentiated. The type locality of A. e. nohlei is the Sierra de Nipe. This range lies to the north of the valley of the Rio Cauto, which separates it from the Sierra Maestra to the south. The Sierra de Nipe is the westernmost portion of the large mountain mass of eastern Oriente. Presently, there is but a single specimen (the type of A. e. nohlei) of A. equestris from this area; in fact, the number of preserved equestris from interior localities in Oriente is very small. The type specimen (MCZ 26653) is a large adult male (snout-vent length about 152 mm) ; despite its length of time in preservative, the head pattern and to a lesser extent the body pattern are still decipherable. The body in life was presumably some shade of green ; presently, it is green with scattered brown dots on one side and brown with scattered buffy spots on the other. These dots are actually restricted to .single scales, although on occasion two or even three adjacent scales 408 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY are unicolored and the "dot" is thus more extensive. The hind- limbs and the tail are obscurely banded with lighter color ; these bands are again actually a vertical series of scales which are set off from the ground color and are usually only one scale in width. Using the distance between the snout and the anterior border of the eye (hereinafter called the snout-eye distance), there are 20 rows of scales vertically, and 24 rows of scales horizontally on the body included in this distance. There are 22 rows of square caudals in the snout-eye distance as well. The top of the head is mottled dark on a light background ; there is more light color than dark. From experience with A. equestris in life, I assume that the light coloration on the head was yellow or white, although pale green is another possibility. The pale head coloration extends posteriorly over the occiput and onto the neck, where there are two irregular pale nuchal blotches (see Figure 2). Laterally, the upper and lower labials are dark; the loreal region is dark, blending gradually into the pale canthal ridge. The canthal ridge continues pale above the eye and merges with an equally pale postorbital spot which in turn is adjacent to the nuchal spot mentioned above. There is a pale green post- labial stripe and a pale green shoulder stripe, both fairly clearly set off from the ground color. The eyeskin is pale brown. There are 11 supralabials to below the center of the eye, and about 45 subdigital lamellae on the fourth toe. Before proceeding, it seems wise to mention the following prob- lems as far as scale counts on these giant anoles are concerned. Barbour and Shreve (1935: 250) diagnosed A. e. noMei partially by means of the number of scales around the body just caudal of the dewlap. In 1958 I rejected this technique as difficult and subject to error, and adopted the snout-eye distance as a stand- ard. The latter is still not completely satisfactory ; at the time of my 1958 paper I was studying anoles principally collected and preserved by myself and party. These anoles were injected with formalin and laid out to harden in metal pans. Thus they had been subjected to more or less uniform procedures, were slightly distended with preservative, and were uncurled and straight. Most scale counts which I have taken previously were on these uniform specimens. However, when working on specimens which at times are desiccated, overly injected and dis- tended, curled in jars, etc., I am well aware that the snout-eye count is subject to tremendous bias. Secondly, the fourth toe subdigital lamellae present a problem. I have usually counted only those subdigital scales which are distinctly broader than SCHWARTZ : ANOLIS EQUESTRIS IN ORIENTE 409 loiiii' and with free edges. These scales occupy roughly the three distal plialaiigos. But in some individuals these scales continue much farther proximally, witliout interruption ; to count to the "normal" stopping place at the end of the third distal phalanx is difficult and subject to error, and I have continued to count these lamellae beyond this point. Such proximad extensions ac- count for some unusually high count.s. There are at hand nine specimens of A. cquestris from tiie area of the Sierra Maestra which differ in several respects from the type of A. e. nohlei. For these lizards from the southern massif in Oriente I propose the name, in allusion to the large-headed males : Anolis EQUESTRIS GALEiFER new subspeclcs Type: MCZ 59326, an adult male, collected near Buey Arriba, southwest of Bayamo, Oriente Province, Cuba, by Kamon Molina and Rodolfo Ruibal, 17 July 1959. Paratijpcs: MCZ 59325, same data as type; AMNH 83627, Las Mercedes, 27 km S Yara, Oriente Province, Cuba, collected by Ronald F. Klinikowski, 7 July 1959; HM 5261 (4 specimens), mountains near Guisa, Oriente Province, Cuba, collected by Thumb, October, 1936; MBZH 142, near Loma del Gato, El Cobre. Santiago de Cuba, Oriente Province, Cuba, collected by C. T. Ramsden and Hno. Cristostamo, no date ; HM 5936, "Oriente," Cuba, collected by Thumb, 1936. Distribution: Apparently the region of the Sierra Maestra from Las Mercedes on the west to Loma del Gato on the east. Diagnosis: A subspecies of Anolis equestris characterized by a combination of large size, moderately-sized dorsal and caudal scales without white skin streaking ; unspotted dorsum ; a prom- inent pale postorbital blotch but no nuchal extension thereof; a short and indistinct postlabial stripe and a prominent and long shoulder stripe ; dewlap pink. Description of type: An adult male with both luMnipenes extruded, snout-vent length 183; tail 340 (all measurements in millimeters) ; dorsals (counted vertically) in snout-eye distance, 19; dorsals (counted horizontally) in snout-eye distance, 21; caudals (counted horizontally) in snout-eye distance, 23; supra- labials to below center of eye, 10; enlarged scales on under- surface of fourth toe, 47. Head longer (54.0) than broad (34.2), snout rather acumi- nate but rounded; canthus rostralis of six enlarged and peaked scales; 38 loreals on one side, the uppermost row more or less 410 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY rugose, the remainder smooth; dorsals quadrate, subquadrate or even rectangular, separated by numerous tiny scales ; 29 en- larged dorsals between slightly smaller and more regular belly scales and medial dorsal row of flaccid crest scales, largest mid- way between fore- and hindlimb insertions on sides ; about 31 smaller scales on belly between lowermost rows of enlarged laterals, gradually increasing in size from midventer laterally ; dorsal surface of limbs covered with pavement-like scales about two-thirds the size of enlarged laterals; ventral surface of limbs covered with scales about one-half the size of midventrals ; ventral edge of dewlap with scales considerably smaller than mid- ventrals, largest anteriorly. Coloration: The preserved specimen is bluish dorsally and dark brown laterally; there is no indication on the dorsum, limbs, or tail, of any dotting, spotting, or crossbanding. The ground color of the limbs is blue, as is that of the tail. The dewlap still has a faint pink tinge and the venter varies from a bluish cream to brown. I gather from the present coloration that this lizard was green in life, with no spotting or crossbanding. The casque is presently dark brown with a minimum of paler spotting ; there are a few isolated spots on the snout and a few on the occipital region. The canthus is pale and expands poster- iorly into a prominent postorbital blotch (see Figure 3). The labials, lores, and eyeskin are dark brown. The postlabial stripe is short and indistinct, and the shoulder stripe is long, dark gray, and likewise indistinct. Variation: The paratypes include four males, two females, and two juveniles ; the entire assemblage varies in snout-vent length from 89 to 173, two of the paratypic males reaching the larger dimension. The type is, as previously noted, larger than either of these two males. Of the males, the three adults re- semble the type closely in pattern; none is spotted, the postlabial stripe is indistinct, and the shoulder stripe is long and fairly prominent. All have a pale canthus and boldly delineated post- orbital blotch. The top of the casque is about as described for the type in one specimen (HM 5261), whereas the remaining two adult males have the casque marked with somewhat more pale areas, with always more dark than light pigmentation. There i.s never an extension of tlie pale area onto the nuchal region, although all four male paratypes show at least an indica- tion of a single pale nuchal spot ; one specimen has a few scattered pale nuchal blotches which are not especially well de- fined. The young male (MBZH 142) has the casque somewhat SCHWARTZ: ANOLIS KQTTKSTRIS IX OKIKXTK 411 iiulistiiu'tly marbled. Tliis li/ard also lacks a postorhital blotch. The two females show much the same variation as the males, althoujih both liave postorhital blotches and some indistinct neck blotchinj?. The shoulder stripe is poorly defined and the labial stripe is likewise not especially prominent, althoup:h it is dis- cernible. The two juveniles also show the postorhital blotch; in these lizards the postlabial and shoulder stripes are more prom- inent than in adults. The dorsal seale.s vary vertically between 17 and 24, vary horizontally between 19 and 28, and there are between 44 and (51 fourth toe lamellae. Altliouji'h I have <>r'ouped the comparisons of the Oriente sub- species of A. equestris at the end of the present paper, it is ap- propriate here to compare .1. (. (jalcifcr with A. e. nohlri. From the outset it should be obviou.s that such comparison is greatly hampered l)v there bein": available but a single specimen of vohlri, as presently defined — i.e., the type. A. c. galeifer differs from Uijbld in having distinctly larger dorsal scales; there are 20 in the snout-eye distance vertically and 24 horizontally in the type of nohlei. These figures are w'ithin the known range of galcifcr; however, inspection of the scales of the type of nohlei shows that they are distinctly smaller than those of comparably sized specimens of galeifer. In this case, observation is more use- ful than actual employment of the vernier : my comments on differences in preservation methods of these specimens in a fore- going paragraph are most pertinent. In addition, the paftei-n of the two races is distinctive: no galeifer has extensive mu'hal blotching as does nohlei. A. c. nohlei is dotted dorsally and has crossbanded limbs and tail ; galeifer does not. The extensive postlabial .stripe in nohlei con- trasts with the absence or reduction of this stripe in galeifer. The shoulder stripe is narrow and long in galeifer, but is bi-oad and long in nohlei. The dewlap coloration in nohlei is unknown ; presently, the dewlap of the type is a faded yellow but this is not trustworthy since Barbour and Shreve (1935:2')1) noted that the dewlap of the type was at the time of their description decidedly pinkish, a much more likely coloration. I have seen one A. e. galeifer, the female from Las Mercedes, in life; the dewlap coloration of this lizard wa.s noted as pink. 1 assume that both nohlei and galeifer have pink dewlaps : there may of course be a difference in pre- cise shade. The situation involving these two subspecies is complicated due 412 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY to the absence of an adequate sample of nohlei. However, the oc- currence of one race of A. equestris in both the Sierra de Nipe and the Sierra Maestra is not likely zoogeographically. The former is separated from the latter by the valley of the Rio Cauto; the form of A. equestris in this valley is presently un- known. It is not improbable that A. e. thomasi occurs there (as noted above), or the valley may be a region of intergradation between nohlei and galeifer. I have previously examined one specimen (USNM 29784) which may possibly be associated with galeifer. This lizard, an adult female, snout-vent 150, is from Guama and is presently not available. My notes indicate that it is unspotted (and thus not assignable to the race described below, nor wuth the dotted nohlei), and that it likewise had no shoulder spots. The village of Guama was located about 40 miles due west of Santiago de Cuba, near the coast (Stejneger, 1917: 260). The dorsal scales of the lizard number 19 vertically and 23 horizontally, and thus are within the known range of galeifer. If the mining camp of Guama was actually in the Sierra Maestra or the foothills of this range, it is most probable that this specimen is representative of A. e. galeifer. It should l)e re-inspected to determine its sub- specific status; for the moment I regard it tentatively as A. e. galeifer. The southern Oriente coast between Cabo Cruz and Cabo Maisi has been shown to harbor a number of races of iguanid lizards of the genus Leiocephalus (Hardy, 1958; Schwartz, 1960) ; two coastal features which seem to have an isolating effect on lizard populations in this region are the Bahia de Santiago and the Bahia de Guantanamo. The same features have played a role in differentiation of A. equestris along the xeric coast. In the area between these two bays, a very distinct subspecies of the Cuban giant anole has developed. I take pleasure in naming this form for James D. Small wood who collected the greater portion of presently available specimens, as : Anolis equestris small woodi new subspecies Type: AMNH 89526, adult male, from Laguna de Baconao, Oriente Province, Cuba, James D. Smallwood collector, 9 August 1960. (Original number 9761.) Paratypes: AMNH 89525, 9.4 mi. W Laguna de Baconao, Oriente Province, Cuba, J. D. Smallwood collector, 9 August I960; AMNH 89527-30, Laguna de Baconao, Oriente Province, Cuba, J. D. Smallwood collector, 17 August 1960. SCHWARTZ: ANOLIS EQUESTRIS IN ORIENTE 413 Distribution: Xeric coast between the Bahia de Santiago and the Bahia de Guantanamo, Oriente Province, Cuba; see, how- ever, discussion below. Diagnosis: A subspecies of Anolis equestris characterized by a combination of moderate size, moderately-sized dorsal and caudal scales without white skin streaking, leopard spotted dorsum (the spots encompassing as many as six adjacent scales and becoming elongate and linear anteriorly), a pale green post- labial stripe and pale greenish-yellow occiput, dewlap pink. Description of type: An adult male, snout-vent length 155; tail 298; dorsals (counted vertically) in snout-eye distance, 19; dorsals (counted horizontally) in snout-eye distance, 22; caudals (counted horizontally) in snout-eye distance, 26; supralabials to below center of eye, 9 ; enlarged scales on undersurface of fourth toe, 48. Head longer (45.3) than broad (30.0), snout rounded; canthus rostrali.s of six enlarged rugose and peaked scales ; 26 smooth loreals on one side ; dorsals quadrate or subquadrate, separated by numerous tiny scales ; 23 enlarged dorsals between slightly smaller and more regular belly scales and medial dorsal row of flaccid crest scales, largest midway between fore and hindlimb insertions on sides; about 29 smaller scales on belly between lowermost rows of enlarged laterals, gradually increasing in size from midventer laterally ; dorsal surface of limbs covered with pavement-like scales about one-third to one-half the size of en- larged laterals; ventral surface of limbs covered with scales comparable in size to midventrals; ventral edge of dewlap with scales slightly smaller than midventrals, largest anteriorly. Coloration : Tn life, dorsum green with pale green leopard-like spotting, the spots involving as many as four adjacent scales and well separated from one another, and becoming linear on the anterior third of the body ; eyeskin greenish gray ; a pale green postlabial stripe onto the neck, bordered above and below by darker green and sharply and prominently delimited both above and below ; shoulder stripe bright yellow ; top of head greenish yellow, the occipital area pale pea-green with scattered dark green blotches; lores pale green mottled with dark green (see Figure 4) ; scales on throat and anterior portion of dewlap dark green; dewlap pink (PI. 2A9 ; color designations from Maerz and Paul, 1950). Hindlimbs with pale green transverse lines, which are also partially indicated proximally on the tail. Venter dark green. 414 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY Variation : The paratypes include two males and three f emaless, varying in snout-vent length from 144 to 159. Coloration of the series is remarkably uniform. A female from 9.4 mi. W Laguna de Baconao had a dewlap which was PI. 1P9 in life (Maerz and Paul) ; the dewlaps in the remainder of the series were noted as grading from faintly orange to pink. All are spotted, although the spotting varies in extent; I cannot detect any difference in spotting between the sexes. The elaborate head pattern is manifested in all, although one female shows it a little less prominently than the remainder of the lot. The dorsal scales vary vertically between 18 and 21, vary horizontally between 18 and 22 ; caudal scales vary between 23 and 26, and there are between 48 and 51 fourth toe lamellae. Inspection of the above data shows that, at least in this restricted sense, A. e. smallwoodi is a small, compact group of lizards with very limited variation in coloration and scalation. A.s one progresses away from the immediate coastal area be- tween the two bays — the type locality of smallwoodi — the situation becomes more complex. There are seven additional specimens from this general area which require some comments. There is a single juvenile (AMNH 89532, snout-vent 61) from Playa Juragua which, when collected, still had the vivid green dor.sal coloration with four creamish-white dorsal bands partly broken into spots. Playa Juragua lies 3.7 mi. east of Siboney, and is thus to the east of the Bahia de Santiago ; I regard this specimen as smallwoodi purely on the basis of provenance. It is possible that the broken condition of the dorsal bands is a characteristic of juvenile smallwoodi ; on the other hand, the broken bands may be merelj^ a transition stage between juvenile and adult patterns. Two specimens from Santiago de Cuba (MCZ 6924; IISNM 58855) and one from 4 km north of Santiago de Cuba (AMNH 89531) are instructive. One of these is a young lizard (snout- vent 97) which shows the dark dorsal coloration and light cross- bands, but in addition clearly shows the pale occiput and in- cipient dorsal spotting characteristic of smallwoodi. The second Santiago de Cuba specimen (USNM 58855) is a young female ; the specimen is presently not at hand, but I have previously examined it. My notes indicate that it has a light nuchal spot behind the occiput and a shoulder spot which is represented by only its own small dark border. There is no mention of any dorsal spotting, pale occipital patches, pale post- labial line, etc. — in fact, nothing to ally it to A. e. smallwoodi. SCHWARTZ : AXOLIS EQUKSTRIS IX OUIKX IK 415 In addition, the dorsal and caudal scale counts (vertical, 10; horizontal, 17; caudal, \H) are extremely small and completely outside the known variation of small ivoodi. Likewise it cannot be regarded as iiohli i or (jaU i(( r Un- reasons of scalation. I can only surmi>e that tliis individual is not from Santiajro, nor for that matter from Oriente; additional inspection is imperative. The third Santiago specimen is from 4 km north of the city, and thus is in the foothills of the Sierra de Boniato at an eleva- tion of approximately 1000 feet {ca. 300 m) ; this specimen was seen alive by myself. It is a young' female (snout-vent 138) which was green in life with the old juvenile bands still i)resent and orange in color. Between the juveinle bands there are vertical rows of spots; the hindlimbs are banded as is the base of the tail. All the above might well be smallwoodi characteristics. The head, however, is dark dorsally, the occipital region is only slightly paler than the dorsum and the postlabial line, although prominent, is not so light nor so prominent as in smallwoodi. The shoulder stripe likewise is somewhat more prominent than in smalhvoodi. Vertical dorsals are 19, and thus within the limits of smallwoodi. I suspect that, despite the absence of the occipital pale areas (a feature which we know from the juvenile specimen discussed above appears very early in life), this lizard should be regarded as the coastal form. Some of its peculiarities may be due to the influence of the adjacent galcifer or another, more northern rather than western, form, as yet unknown. A fine well preserved adult male (MBZH 260) from Hongo- losongo is another puzzle. Hongolo.songo lies to the west north- west of El Cobre and is on the northeryi slope of the Sierra del Cobre to the west of the Bahia de Santiago. I have no doubt that this individual is referable to smallwoodi ; it possesses the pale head and occiput, dor.sal spots, etc., and the scales are completely within the range of topotypic smallwoodi. If we a'>sume that the two available specimens from the area of Santiago de Cuba (eliminating the single peculiar USNM specimen as noted above) represent smallwoodi, then clearly there is no gap between coastal specimens from ea.st of the Bahia de Santiago and the single individual from Ilongolosongo. It is remarkable, however, that a lizard which occurs in the xeric coastal plain in this region should also occur on the noi'th side of a somewhat removed range of mountains, but such indeed seems to be the case. Apparently the races smallwoodi and galcifer intergrade somewhere between Loma del Gato and Hongolosongo, a distance of about thirty miles. 416 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY There are two available specimens from the coast (or nearly so) west of the Bahia de Santiago. One of these (USNM 29784) from Guama has already been commented upon under the dis- cussion of A. e. galeifer, with which race I temporarily associate it. The absence of dorsal spotting disqualifies it at once as being smallwoodi. The other lizard (MCZ 42480) is a juvenile (snout- vent 50) from the coast south of Pico Turquino. It shows the typical juvenile pattern and coloration, and there is nothing distinctive about it. Since it is coastal (P. J. Darlington coll.), it may be assignable to smallwoodi. Only additional specimens from this region will allow a definite subspecific allocation. When in 1958 I examined the available material from Oriente, there was a single specimen from the Rio Yateras (CM 33320) which was so unusually patterned that it was only with extreme uncertainty that I assigned it to nohlei. Since that date, another such specimen has come to light (MCZ 68921). In addition, I have examined still another specimen which I regard as belong- ing to this same heavily spotted form, for which I propose the name palardis as an anagram of the Latin word pardalis, mean- ing "leopard." Anolis equestris palardis new subspecies Type: CM 33320, adult male, Rio Yateras, 5 mi. north of the river mouth, Oriente Province, Cuba, Wm. McLane and R. H. Wilkinson, collectors, 16 September 1952. Paratype: MCZ 68921, Guantanamo (U. S. Naval Base), Oriente Province, Cuba, R. Lando, collector, 1962. Distribution: Apparently the Guantanamo Basin and east- ward along the southern Oriente coast presumably at least as far as Baitiquiri. Diagnosis : A subspecies of Anolis equestris characterized by a combination of moderate size, moderately-sized dorsal and caudal scales without white skin streaking, heavily spotted or almost reticulate dorsum, the spots encompassing as many as fourteen adjacent scales and parts thereof and becoming elongate and linear anteriorly, prominent pale postlabial and shoulder stripes, a prominent pale postocular patch, upper surface of casque dark with discrete pale flecking or with more extensive pale marbling. Description of type: An adult male, snout-vent length 150; tail (incomplete and regenerating) 120; dorsals (counted vertic- ally) in snout-eye distance, 14; dorsals (counted horizontally) in snout-eye distance, 16; caudals (counted horizontally) in SCHWARTZ : ANOLIS EQUESTRIS IN ORIENTE 417 snout-eye distance, 14 ; supralabials to below center of eye, 10 ; enlarged scales on undersurface of fourth toe, 59. Head longer (45.0) than broad (28.0), snout rounded; canthas rost rails of six enlarged rugose and peaked scales; 32 smooth loreals on one side; dorsals quadi'ate to subcircular, separated by numerous tiny scales ; 28 rows of enlarged dor.sals between slightly smaller and more regular belly scales and medial dorsal row of flaccid crest scales, largest midway between fore- and hindlimb insertion on sides ; about 8G smaller scales on belly between lowermost rows of enhirged laterals, the midventral scales only slightly smaller than the lower row of laterals; dorsal surface of limbs covered with pavement-like scales about one- third to one-half the size of enlarged laterals ; ventral surface of limbs covered with scales two-thirds the size of midventrals ; ventral edge of dewlap with scales slightly smaller than mid- ventrals, largest anteriorly. Coloration: The preserved specimen is almost chocolate brown, the entire dorsum covered with rather large and very prominent pale spots, the largest encompassing six adjacent scales; both fore- and hindlimbs are erossbanded with pale buffy, and the proximal portion of the tail is especially prominently erossbanded with narrow bands one to three scales in width. The dorsal surface of the head is dark brown with clear and discrete white flecks scattered more or less uniformly ; the occiput is dark with a few white flecks like those on the casque, and these extend onto the neck where there is a single larger white spot. The canthus and eyeskin are pale and there is a conspicuous and clearcut white postorbital blotch ; the postlabial stripe is somewhat less prominent and the shoulder stripe is very long, not quite so pale, and extends almost half-way along the body beyond the forelimi) insertion (see P'igure 5). There is a peculiar pale U- shaped figure over the sacrum which is washed with brown and which even now stands out conspicuously among the large dorsal spots. The ventral surface is dark; both supra- and infralabials are dark centered and pale edged ; the throat is more or less clouded longitudinally with dark brown. The dewlap is pres- ently entirely w'hite. Variation: The single paratype is a rather poorly preserved adult male with a snout-vent length of 168. The coloration and pattern resemble those of the type very closely except that the body spots are even larger and more extensive, involving as many as fourteen adjacent scales. The limbs and tail are boldly 418 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY banded, the bands on the tail as wide as three caudal scales. The casque is likewise more prominently .spotted than that of the type. Other head and stripe details are comparable between the two, except that the postlabial and shoulder stripes are paler and thus show more contrast with the almost black ground color. The dewlap is still faintly pink. Scale counts on the paratype are : vertical dorsals, 18 ; horizontal dorsals, 24 ; caudals, 24 : fourth toe lamellae, 45. The difference in size of dorsals between the type and paratype is doubtless an artifact of preservation since by inspection the size of the dorsals does not seem to differ strikingly. As with A. e. smallwoodi, once the immediate region of the type locality is left, the specimens become problematical. There are available five other lizards which in theory should be assign- able to palardis. Each will be discus.sed separately. There is a young adult male (MCZ 42552) from Imias, which lies about 35 miles to the southeast of Guantanamo, on the coast ; this locality is the farthest east from which A. equestris is known. I find it very difficult to assign this individual to palardis, to which race it might reasonably be expected to belong on the basis of geography. The body shows no signs of spotting of any sort ; on the other hand, there is a large, conspicuous, dark bordered nuchal spot, and some dissociated spots on the occipital region. The casque is apparently marbled as in palardis, however. There is a pale postorbital spot, a pale and prominent i)ostlabial stripe, and a fairly well exj^ressed shoulder stripe, although the latter is not so bold nor so clear a.s that in palardis. Also, the dorsal scales are much smaller than are those of any specimens of palardis. There are two possibilities: 1) the lizard came from the mountains to the north of Imias, and thus represents still another Oriente race; 2) the lizard came from the coast at Imias and there is another subspecies of A. equestris along the southern Oriente coast beyond Baitiquiri, and thus including Imias. I prefer to believe that the former is the correct interpretation. It is even conceivable that A. e. galeifer extends this far east throughout the southern Oriente mountains. The Imias lizard in some pattern details resembles the more western race. IIoAvever, the small size of the scales prevents tliis si)eeiim'n from being associated with galeifer. An adult female from Baiti(|uiri (MCZ 42551) agrees very well with the type and paratype insofar as head pattei-n is con- cerned, and in fact seems to combine the cas(|ue flecks of ihe type with the more blotchy casque markings of the ]iaratyi)e. The SCHWARTZ : ANOLIS KQUESTRIS IN ORIENTE 419 body is not particularly sjxjttcd ; witli a little imagination one can visualize the remnants of spots on the back and sides, but if they were present, tiiey were probably not so vivid and prom- inent a.s described above. At least the neck is marked with eloni^ate pale blotches and streaks very comparable to those of the paratype. I rejifard this specimen as palardls. Three specimens from the environs of Guantananio (MCZ 8977, a juvenile, snout-vent 47, from "near Guantananio"; USNM 58057, an adult female, and MCZ 57928, an adult male, both from Guantananio) are especially puzzling. Of these the juvenile lacks any characteristics which would alif?n it with palardis; it is interesting, however, in that, of the few juveniles available from Oriente, it alone has a prominent pale green I)ostlabial stripe. l^SNM 58057 is not available at the moment, but my notes on it state that it has a large and elaboi'ate shoulder spot ; obviously the specimen i.s not entirely spotted as are the type and paratype of palardis. The presence of the shoulder spot may again indicate the same situation as noted above for the Baitiquiri specimen, i.e., a remnant of the more extensive pattern. The final Guantananio specimen, MCZ 57928, is distinctly dif- ferent from the typical material. The casque is entirely marbled with pale color. The postorbital spot is absent but there is a bi'own patch in the area bounded above by a raised i)atch of pale scales ; the postlabial and shoulder stripes are not pale or especi- ally prominent, and the dorsum shows only faint indications of having been spotted in life. Again, if this specimen came from ''Guantananio" in a broad sense only, and not from the lowlands in the Basin itself, it is likely that it is not palardis but some other race from the mountains to the north. T regard it only provisionally as palardis. In the summer of 1959, I secured three A. equestris from Baracoa on the northeastern coast of Oriente. The dewdap colora- tion of these lizards was so very distinct that it was obvious they represented a new subspecies; Dr. Williams had also come to the same conclusion based upon three specimens in the collection at Harvard, but he has graciously allowed me to describe this new race as : Anolis equestris baracoae new subspecies Type: MCZ 57404, adult female, Baracoa, Oriente Province, Cuba, P. A. Adams, collector. 4 April 1958. 420 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY Paratypes: MCZ 47050, Joar, Baracoa, Oriente Province, Cuba, G. Canet, collector, 1943 ; AMNH 83628, Baracoa, Oriente Province, Cuba, native collector, 11 August 1959 ; AMNH 83629-30, Baracoa, Oriente Province, Cuba, native collector, 13 August 1959. Distribution: Known only from the type locality. Diagnosis: A subspecies of Anolis equestris characterized by small size, extremely small dorsal scales and long dorsal crest scales, dorsum either plain green or green with pale blue small dots or flecks, a small and relatively inconspicuous postorbital patch, shoulder stripe and postlabial stripe inconspicuous and short, dewlap bluish-green. Description of type: An adult female, snout-vent 158, tail 186, regenerated tip; dorsals (counted vertically) in snout-eye distance, 26; dorsals (counted horizontally) in snout-eye dis- tance, 33; caudals (counted horizontally) in snout-eye dis- tance, 29 ; supralabials to below center of eye, 9 ; enlarged scales on undersurface of fourth toe, 42. Head longer (43.7) than broad (25.0), snout rounded; canthus rostralis of six enlarged rugose scales ; about 36 smooth loreals on one side; dorsals subcircular, separated by numerous tiny scales ; dorsal crest scales elongate ; 38 enlarged dorsals between slightly smaller and more regular belly scales and medial dorsal row of flaccid crest scales, largest midway between fore- and hindlimb insertions on sides; about 30 smaller scales on belly between lowermost rows of enlarged laterals, gradually increas- ing in size from midventer laterally ; dorsal surface of limbs covered with pavement-like scales about two-thirds the size of enlarged laterals; ventral surface of limbs covered with scales about one-half the size of midventrals ; ventral edge of dewlap with scales one-half the size of midventrals, not appreciably en- larged anteriorly. Coloration: In preservation, dorsum pale bluish -gray dotted with pale spots which are more or less linear and involve as many as four longitudinally adjacent scales. Dorsal surface on hindlimbs rather obscurely crossbarred with darker ; forelimbs with a few pale scales which apparently indicate crossbands in the living animal. Casque pale blue dorsally with no pale mai'kings; a pale blue postorbital blotch, a very indistinct post- labial stripe and a fairly extensive dark shoulder stripe (see Figure 6). Loreals and supralabials marbled with dark blue; throat clouded with dark ; venter immaculate pale blue. SCHWARTZ : ANOLIS EQUESTRIS IN OBIENTE 421 Variation: The four female paratypes vary in snout-vent length from 120 to 145, and are thus all smaller than the type. One (AMNII 8;]628), the smallest, is colored quite comparably to the type; another (AMNH 83630) is very dark and is flecked with isolated and discrete tiny dots dorsally ; the remainino; two specimens are bluisii-gray dorsally without any dots or flecks, but show some irregular pale nuchal areas, and one of these has a fairly bold and prominent postorbital patch. In none are the postlabial and shoulder stripes really well defined. In the three live specimens which I have seen, the dewlap color was noted as blue or blue-green. It is unfortunate that all the specimens of haracoae are females, but judging from my experience with other races, the dewlap coloration is very close in the two sexes. The small size of the dorsal scales is manifested in the follow- ing figures : vertical dorsals, 25 to 27 ; horizontal dorsals, 23-26 ; horizontal eaudals, 20-29. In addition to the type and paratypes, I have seen one juvenile (MCZ 42520, .snout-vent 48) ; interestingly, the dorsals on this small lizard are indeed tiny and thus conform with the small scales of haracoae. Also, the lizard shows none of the dorsal crossbars which are usually typical of very young A. equestris. This patternless condition may be a character of juvenile baracoae. It is appropriate here to discuss one other lizard from the environs of Baracoa. It is an adult female (AMNII 83631), snout-vent 160, from 8 miles northeast of Felicidad. This locality lies more or less equidistant between Guantanamo on the south and Baracoa on the north. The lizard might be reasonal)ly sup- posed to be assignable either to haracoae or to some intergradient population between haracoae and palardis. The former is cer- tainly not the case, since the dewlap was recorded in life as being pink. Likewise my color notes in life (dorsum green with light green dots which turned brown after death ; head brown with cream colored casque, flecks extending onto the nape and a few on dorsal crest scales; lips, labial stripe and shoulder stripe bright green ; no occipital or shoulder blotches ; dewlap scales pale yellow on a pink — PI. 1E7 — skin) indicate that this lizard was not colored as is haracoae. The dorsal scales (vertical 23; horizontal, 21) are also perceptibly bigger than in haracoae and the dorsal crest scales are not high and elongate. In some ways this specimen resembles ]\ICZ 57928 from Guantanamo, but it is just as distinctly different. I regard it pro tern as a representa- tive of a race from the mountains of interior of eastern Oriente. 422 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY Four specimens of A. equestris from the region of Moa on the north Oriente coast represent still another indigenous subspecies, which may be called, in allusion to the pebbly appearance of the dorsal surface of the casque : Anolis equestris saxuliceps new subspecies Type: HM 5376, adult female, Moa, Oriente Province, Cuba, Thumb, collector, between April and November, 1938. Paraiypcs: HM 5376 (smaller of two specimens bearing this number), same data as type; HM 5374, same data as type; MCZ 59324, cfl. 7 km B Moa, Oriente Province, Cuba, R. Molina and R. Ruibal, collectors, 21 July 1959. Distribution: Known onl}- from the immediate environs of Moa. Diagnosis: A subspecies of Anolis equestris characterized by a combination of moderate size, moderately sized dorsal and caudal scales without white skin streaking, dorsal coloration ap- parently somewhat dotted or spotted, prominent and dark bordered postlabial and shoulder stripes, absence of postorbital blotch, dorsal surface of casque with a reticulate or marbled appearance, spotted labials, dewlap pink. Description of type: An adult female, snout-vent length 146; tail 187; dorsals (counted vertically) in snout-eye distance, 20; dorsals (counted horizontallj-) in snout-eye distance, 21 ; caudals (counted horizontally) in snout-eye distance, 24; supralabials to below center of eye, 10 ; enlarged scales on undersurface of fourth toe, 44. Head longer (42.2) than broad (25.9), snout rounded; canthus rostralis of 6 enlarged rugose scales ; 43 loreals on one side, smooth except that the two upper rows are somewhat rugose ; dorsals subquadrate, separated by numerous tiny scales ; 29 en- larged dor.sals betM^een slightly smaller and more regular belly scales and medial dorsal row of flaccid crest scales, largest mid- way between fore- and hindlimb insertions on sides; about 33 smaller scales on belly between lowermost rows of enlarged laterals, gradually increasing in size from midventer laterally ; dorsal surface of limbs covered with pavement-like scales about one-half the size of enlarged laterals ; ventral surface of limbs covered Avitli scales about one-half the size of midventrals ; ventral edge of dewlap with scales slightly smaller than mid- ventrals, not appreicably larger anteriorly. SCHWARTZ : ANOLIS EQUESTRIS IN ORIENTE 423 Coloration: Tho typo is now dark l)rown dorsall}-, and dirty bluish pray ventral ly. The middorsal area has a few scattered lipht blue scales, and tlicre is a taint indication of at least two vertical lateral bands of buft'y scales between the limbs. I do not know exaetl}' what the significance of these details is, havinf? never seen saxidiceps in life. Tt is pos-sible that dorsally the lizard was green in life with some middorsal pain- flecks and a pair of pale green lateral bars, all of which likelj' M'ere rather inconspicuous. The hiudlimbs are unmarked, whereas the fore- limbs and dorsal surface of the hand show some paler scales, which at least on the forearm are organized into erossbands. The most striking feature is the gravelly appearance of the casque. Each scale on the dorsal surface of the cascjue is pale centered and dark edged, giving the casque a more or le.ss uni- formly marbled or even reticulate appearance; this pattern con- tinues posterioi'ly over the top of the head as far as the occiput and into the postorbital region (which is indistinctly and finely marbled), then blends imperceptibly into the dorsal body dotting mentioned above. The lores, supra- and infralabials are likewise pale with much dark marbling, the dark pigment on the labials being placed at the sutures between the scales, rather than in the center of the scales (see Figure 7). The eyeskin is dai-k brown. The mental area is dull blue, grading quickly to very dai'k brown at al)out the level of the anterior edge of the dewlap, and this brown coloration continues posteriorly to the forelimb insertion. The dewlap skin is presently dirty cream. The postlabial line is pale blue, clearest anteriorly but still very obvious and bordered above and below with darker on the neck. The shoulder stripe resembles the postlabial stripe in clearness, definition, and in being bordered with darker above and below. Variation: The three paratypes are females, one of which is rather immature, ranging in snout-vent length from 112 to 132. As far as head pattern is concerned, all resemble the type very closely. The same is true of body pattern and coloration, except for the smallest (HM 5374). This young female has a streaked dorsum, the individual streaks involving three scales on the body itself, and more in the scapular region. The neck is almost reticulate, there being more pale than dark areas. Whether this peculiar pattern reflects the juvenile pattern or whether such a condition is merely a part of the variation of saxidiceps is un- known. Certainly there is no doubt that this individual repre- sents this taxon ; the casque pattern is diagnostic. 424 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY The paratypes vary scalewise in that there are between 18 and 23 dorsals vertically, between 23 and 27 horizontally ; caudals range from 24 to 25, and fourth toe scales between 44 and 50. The dewlaps in two of the specimens of saxuliceps are still faintly pink. I assume that, despite the fact that all known saxuliceps are females, the dewlap coloration in males is pinkish. This coloration is quite different from the blue-green dewlap of haracoae to the east. COMPARISONS AND DISCUSSION With the description of five new races of Anolis equestris from Oriente, there are now nine subspecies from Cuba and another (hassleri) from the Isla de Pinos. Rather than inserting the comparisons between the named forms in their proper places in the descriptions, I am amassing them here for greater simplicity. Table 1 shows the range of scalation of the ten forms. Table 1 Dorsal and caudal scale characteristics of ten populations of Anolis equestris. No, Dorsals Dorsals Caudals Subspecies (vertical) (horizontal) (horizon' luteogularis 40 14-22 16-22 19-28 equestris 42 10-19 10-17 14-22 thomasi 17 7-11 7-12 11-17 noblei 1 20 24 22 galeifer 9 17-24 19-28 21-26 smallwoodi 6 18-21 18-22 23-26 palardis 3 14-18 16-24 12-24 haracoae 6 25-27 23-33 20-29 saxuliceps 4 18-23 21-27 24-25 hassleri 4 15-19 16-21 19-23 The races smallwoodi, palardis, and in some cases haracoae and saxuliceps, all differ from thomasi in that they possess spotted dorsa ; thomtasi never has such a feature and is character- ized by white longitudinal streaking instead. Also thomasi is characterized by having exceptionally large scales, whereas all the new Oriente races are smaller scaled, with haracoae at the extreme. From A. e. equestris the Oriente races differ in dewlap color (haracoae), dorsal spotting (smallwoodi, palardis), and head and casque pattern (saxuliceps, nohlei, galeifer). In addition, haracoae at least is completely separable from the race equestris SCHWARTZ : ANOLIS EQUESTRIS IN ORIENTE 425 426 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY on size of dorsals ; smallivoodi and saxuliceps are practically separable from equestris on this same character, although there is a small amount of overlap. From luteogularis, a dotted form in extreme western Cuba ("with scattered specks of pale yellow on a green background," Schwartz, 1958: 5-6), the spotted Oriente races (smallwoodi, palardis) differ in much larger spots on the dorsum (in contrast to flecks which involve only part of a scale rather than several adjacent scales) ; haracoae differs in a blue-green rather than orange or j^ale yellow dewlap and much smaller dorsals ; nohlei, galeifer, saxuliceps differ in much more complex head patterns. The five new Oriente subspecies may be differentiated as fol- lows: 1) haracoae has small dorsals and a blue-green dewlap; 2) smallwoodi is spotted dorsally and has the occipital region pale green; 3) palardis has heavy, almost reticulate, dorsal spotting without pale occiput and with a pale postorbital patch ; 4) saxuliceps has a marbled or reticulate casque, spotted lores and labials, and lacks a postorbital blotch; 5) galeifer is un- spotted, with a pale postorbital blotch without a nuchal exten- sion. For detailed comparison of galeifer with noMei, see the discussion of the former form. Nohlei differs from the remaining Oriente races in having a pink dewlap (blue-green in haracoae) , having small dorsal dots (in contrast to heavy spotting in smallwoodi and palardis), having a mottled casque rather than a marbled or quasi-reticulate one (as in saxuliceps) , and from all Oriente races grouped together in having a nuchal extension of the pattern of the casque and occiput. It is obvious that there still remain many problems in the distribution of A. equestris in Oriente. We have no real data on the area of intergradation (or even the precise distributional relationships) of thomasi with any of the Oriente races. The distribution and variation of nohlei is unknown. The precise situation in the environs of the cities of Santiago de Cuba and Guantanamo is confused, due probably to improper labeling of specimens and lack of distinction between specimens taken in the cities and near them, especially in the foothills and mountains to the north. The identity of the race along the southern coast between Cabo Cruz and the Bahia de Santiago is indeterminate. Specimens are badly needed from the central portion of the mountain massif in the eastern part of the province, the single individual from near Felicidad and the one from Tmias give promise of increased complexities in this region. SCHWARTZ : ANOLIS EQUESTRIS IN ORIENTE 427 SPECIMENS EXAMINED (All from Orientc I'l-dviiu-e, Cuba) Anolis cqiKstrls (hoinasi (10): (iibara, :} (A. Schwartz col- lection 285) ; Bancs, 4 (AS 28Gj ; Los Angeles, 5 nii. E Banes, 2 (MCZ 25153-54); Cabo Cruz, 1 (AMNH 83632). Anolis c. nohlci (1) : Sierra de Nipe (MCZ 26653). Anolis c. (jalcifer (9) : nr. Buey Arriba, SW Bayanio, 2 (MCZ 59325-26) ; nr. Loma del Gate, 1 (MBZII 142) ; Las Mercedes, 27 km S Yara, 1 (AMXII 83627) ; mountains near Guisa, 4 (HM 5261) ; "Oriente," 1 (IIM 5936). Guama, 1 (USNM 29784) is questionably associated with galcifer. Anolis e. sinalhroodi (10) : 9.4 mi. W Laguna de Baconao, 1 (AMNH 89525); Laguna de Baconao, 5 (AMNH 89526-30); Hongolosongo, 1 (MBZH 260) ; Playa Juragua, 1 (AMNH 89532) ; Santiago de Cuba, 1 (MCZ 6!)24) ; 4 km N Santiago de Cuba, 1 (AMNPI 89531). Anolis e. palardis (3) : Rio Yateras, 5 mi. N river mouth, 1 (CM 333200); Baitiquiri, 1 (MCZ 42551); Guantanamo (U.S. Naval Base), 1 (MCZ 68921). Anolis e. baracoiK (6): Joar, Baracoa, 1 (MCZ 47050); Ba- racoa, 5 (AMNH 83628-30; MCZ 57404; MCZ 42520). Anolis e. saxuliccps (4): Moa, 3 (ini 5376(2); HM 5374); ca. 7 km E Moa, 1 (MCZ 59324). Anolis cqucstris inccrtae sedis: Santiago de Cuba (USNM 58855) ; coast south Pico Turquino (MCZ 42480) ; nr. Guan- tanamo (MCZ 8977); Guantanamo (USNM 58057; MCZ 57928) ; Imias (MCZ 42552) ; 8 mi. NE Felicidad (AMNH 83631). LITERATURE CITED Barbour, Thomas, and Benjamin Shreve 1935. Notes on Cuban ancles. Occ. Papers Boston Soc. Nat. Hist., 8:249-253. Hardy, Jerry D., Jr. 1958. A new lizard of the genus Lciocrplialus from Cuba (Squaniata: Iguanidae). Jour. Washington Acad. Sci., 48(9) :294-300, 5 tigs. MAEitz, A., AND M. Rea Paul 1950. A dictionary of color. New York, McGraw-Hill Book Co., pp. i-vii, 1-23, 137-208, 56 pis. Marrero, Levi 1951. Geografia de Cuba. Habaua, Alfa, pp. i-xvi, 1-736, 478 figs. 428 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY Schwartz, Albert 1958. A new subspecies of Anolis equestris from eastern Cuba. Herpe- tologJea, 14(1): 1-7, 1 fig. 1960. Variation in tlie Cuban lizard Leioceplialus raviceps Cope. Proe. Biol. Soc. Washington, 73:67-82, 10 figs. Stejneger, Leonhard 1917. Cuban amphibians and reptiles collected for the United States National Museum from 1899 to 1902. Proc. U.S. Nat. Mus., 53:259-291, 128 figs. PLATE BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY ^ ft s QJ S. '*"^ a K m e 0 -:=! !=?> ca 3 ^ CO ai CO CO CO 4h 0 O ^ ^ — CQ » .cc na n ^ cS t^ ;^ Q 5 S CO 10 .2" ^ s o3 •«!i> ^ ft w a s ^-^ a 0 si =0 .0 (m" 10 • fH Oi TJ bJb OO S e a 03 S „- s bi 03 ^ s '0 eS ^ •^ ,^^ ^^ '« 4) » 0 ft cS 0 ^ m OJ £ 2 s O ' w SCIIWART/: AXOI.IS IX^I'KSTHIS IX OHIKXTE Bulletin of the Museum of Comparative Zoology HARVARD UNIVERSITY Vol. 131, No. 13 THE LYNX SPIDERS OF NORTH AMERICA, NORTH OF MEXICO (ARANEAE : OXYOPIDAE) Bv Allen R. Brady CAMBRIDGE, MASS., U.S.A. PRINTED FOR THE MUSEUM September 30, 1964 Publications Issued by or in Connection WITH THE MUSEUM OF COMPARATIVE ZOOLOGY HARVARD UNIVERSITY Bulletin (octavo) 1863 — The current volume is Vol. 131 . Bbeviora (octavo) 1952 — No. 207 is current. Memoirs (quarto) 1864-1938 — Publication teruiinaied \\ iih Vol. 55. Johnsonia (quarto) 1941 — A publication of the Depariinent of Mollusks. Vol. 4, no. 41 is current. , Occasional Papers of the Department of Mollusks (octavo) 1945 — Vol. 2, no. 28 is current. Proceedings of the New England Zoological Club (octavo) 1899-1948 — Published in connection with the Museum. Publication terminated with Vol. 24. The continuing publications are issued at irregular intervals in nuiii- bers which may be purchased separately. Prices and lists may be obtained from the Publications Office of the Museum of Comparative Zoology, Cambridge 38, Massachusetts. Peters' Check-List of Birds of the World. Volumes 1, 4 and 6 are out of print ; volumes 2, 3, 5, 7, 9, 10 and 15 are currently available. Phylogeny and Evolution of Crustacea. Proceedings of a confer- ence held at Cambridge, Mass., March 6-8, 1962. H. B. Whittington and W. D. I. Rolfe, editors. Cambridge, Mass., 192 pp., 80 figs., 1963. Cloth bound, $6.75. Fishes of the Gulf of Maine, by Henry B. Bigelow and William C. Schroeder. Washington, viii - 577 pp., 1953. Photo-offset reprint, $6.50. Publications of the Boston Society of Natural History The remaining stock of the scientific periodicals of the Boston Society of Natural History has been transferred to the Museum of Comparative Zoology for distribution. Prices for individual numbers may be had upon request. Bulletin of the Museum of Comparative Zoology HARVARD UNIVERSITY Vol. 131, No. 13 THE LYNX SPIDERS OF NORTH AMERICA, NORTH OF MEXICO (ARANEAE : OXYOPIDAE) By Allen R. Brady CAMBRIDGE, MASS., U.S.A. PRINTED FOR THE MUSEUM September, 1964 Bull. Mus. Conip. Zool., Ihiivaid I'liiv., 131 (13) :429-r)18 Septomber 19()4. No. 13. — THE LYNX SPIDERS OF NORTH AMERICA, NORTH OF MEXICO {ARANEAE: OXYOI'JDAE)^ By Allen R. Brady CONTENTS Page Introduction i'.VI Genera of Oxyopidae 433 Superfamily Lycosoidea 435 Biology of the Oxyopidae 436 Acknowledgments 438 Walckenaerian Names 439 Methods 442 Taxonomic Section Oxyopidae Thorell 444 Key to Genera 446 Oxyopes Latreille 447 Species Groups of Oxyopes 448 Key to Species of Oxyopes — Males 452 Key to Species of Oxyopes — Females 453 Oxyopes acleistus Chamberlin 454 Oxyopes aureus sp. n 457 Oxyopes aglossus Chamberlin 461 Oxyopes occidens sp. n 464 Oxyopes apollo sp. n 467 Oxyopes floridanus sp. n 469 Oxyopes tridens sp. n 472 Oxyopes pardus sp. n 474 Oxyopes lynx sp. n. 475 Oxyopes felinus sp. n 476 Oxyopes salticu^ Hentz 478 Oxyopes . scalaris Hentz 484 Hamataliwa Keyserling 496 Eamataliwa helia (Chamberlin) 497 Hamataliwa unca sp. n. 499 Hamataliiva grisea Keyserling 501 Feucetia Thorell 505 Peucetia viridans (Hentz) 506 Peucetia longipalpis F.O.P.-Cambridge 512 List of Collectors 515 Literature Cited 516 1 This study was presented to the Department of Biolopy at Harvard Univer- sity in partial fulfillment of the requirements for the degree of Doctor of Phi- losophy. 432 BULLETIN : MUSEUM OP COMPARATIVE ZOOLOGY INTRODUCTION The family Oxyopidae comprises 371- described species dis- tributed chiefly throughout the tropical and subtropical regions of the world. This investigation is concerned with the evolution- ary relationships and distribution of those species occurring north of Mexico. Of the 17 species involved, most occur only in the southern United States, but several occur over wide areas in the temperate and colder regions of North America. Oxyopcs salticus and 0. scalaris are found from coast to coast, and 0. scalaris ranges from British Columbia and Labrador to northern Mexico. It is of interest that several widely distributed species of Oxyopes are also found in the temperate regions of Europe and Asia. Large collections from Central America, Mexico and the West Indies were examined to determine the range of the oxyopids found north of Mexico. This study also illuminated the rela- tionship between the Mexican, Central American and West Indian faunas and that of temperate North America. A pre- liminary examination of the species occurring in the Neotropical region reveals that the number of described species of Oxyopidae will almost certainly be doubled when the tropical regions have been fully investigated. The oxyopid types of 0. Pickard-Cambridge and F. 0. Pickard- Cambridge (1894, 1902), deposited in the British Museum (Nat- ural History), were examined as a part of this study. Their examination provided the information that determined whether or not the names used by 0. P.- and F. 0. P.-Cambridge should be applied to any of the oxyopids found north of Mexico. C. A. Walckenaer (1838, 1841) in his "Histoire Naturelle des Insects" described six species of Oxyopidae from the Georgia region of the United States. These descriptions were based on the drawings in the unique manuscript of John Abbot (1792). The drawings are expertly done and adequate for identification of some species. However, it is often difficult or impossible to decide on the basis of color pattern what species is figured, and only if the specimen were at hand, or the genitalia figured, could one make an accurate decision. Walckenaer had few specimens to guide him and frequently placed spiders in the wrong family, e.g. Sphasus vittatus Walckenaer is obviously a clubionid, not an oxyopid. The Abbot manuscript, also deposited in the British 2 Based on latest records in the Zoological Record, vol. 98, sect. 12, 1961. BRADY : LYNX SPIDERS 01-^ NORTH AMERICA 433 Museum (Natural History), was examined and the drawings photographed. These colored photographs are deposited in the Museum of Comparative Zoology. The names pertaining to the Oxyopidae that AValekonaer applied to the drawings of Abbot and Bosc (1800) are discussed below. GENERA OP OXYOPIDAE Eleven genera are placed in the O.xyopidae at present. The number of species and the geographical distribution of species are listed in Table I. This list, based on that of Roewer (1954), includes the species described through 1961. Of the eleven genera listed, I have examined representatives of five {Oxyopes, Hama- taliwa, Peucetia, Oxyopeidon, and Tapinillus) m collections from the entire world, with particular attention to those species occurring in North America, Mexico, Central America and the "West Indies. From this study I conclude that Oxyopeidon must be sjaionymized with Hamataliwa, as Bryant (1948) has already pointed out. The genus Oxyopeidon was differentiated from Hamataliwa by the position of the anterior median eyes (AME) and by the spacing of the posterior median eyes (PME). Not only do such differences occur between closely related species, but these differences in eye arrangement may occur between sexes of the same species. The genus Hamataliwa is, therefore, redefined. From the descriptions in the literature it is apparent that the genus Lacsfrygones Urquhart is not an an oxyopid and should be removed from the Oxyopidae, as has been done by Bryant (1933) and Forster (1955). The descriptions of Hostus paroculus Simon and Pseudohostus squamosus Rainbow, the type species of monotypic genera, place them well wathin the range of variation found among species of Oxyopes. Simon (1898) places Meguilla trxmcaia Thorell, an- other type species, in the genus Hamataliwa where it probably belongs. Remaining in the family Oxyopidae, then, are six valid genera: Oxyopes, Peucetia, Hamataliwa, Tapinillus, Schaenios- celes, and Tapponia. Laestrygones should be removed from the Oxyopidae. Oxyopeidon most certainly and Meguilla probably should be synonymizecl with Hamataliwa. The monotypic genera Hostns and Pseudohostus are probably synonyms of Oxyopes. The structure of the genitalia, particularly of the male palpus, serves as an accurate indicator of generic as well as specific rela- tionships. The above conclusions regarding the placement of 434 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY genera were based on characters of the genitalia together with general body form and color, and the relative length of the legs. The arrangement of the eyes and the width of the various eye rows prove useful in separating some genera (Tables II and III), but they were not used as the primary basis for establishing genera, as in the past. The examination of oxyopids from all parts of the world has indicated that the genus Hamataliwa, Table I GENERA OF OXYOPIDAE Genus Geographical Number tI^££rS_p_e_c_!jjJ Author _D.'JJli^L'fi?_ °f APli'AL Ui'JM.'i'iLwS Keyserling, 1887 Neotropical 14 (gHsea) H^JiJil Simon, 1898 Madagascar I <£5L°5.y.L4A} Ljjestr^iones^ Urquhart, 1-894 New Zealand and 3 (ii^'JLlTJj) Subantarctic Isls. MAM-UI?. Thorell, 1897 Indochina I (truncal a) Ojcj^jjidon 0. P. -Cambridge, 1894 Ethiopian 5 rpufum) Neotropical 24 Ojcy^jej Latreille, 1804 Palaearctic 19 (heteroDhthalmus) Ethiopian 93 ^ Oriental 45 Malay Peninsula to New Guinea I Australian 23 Neotropical 47 Nearctic 1 1 E3J^S3lL%. Thorell, 1869 Palaearctic 5 (viridis) Ethiopian 25 Oriental 4 Australian 2 Neotropical 22 Neotropical and Nearctic I fj^i)i.dj)ji^jius Rainbow, 1915 Australian I (squam_o_sjj_s) SiJ?jei>ioi££iLS_ Simon, 1898 Neotropical 7 (elegans) Jj^inLL'jJ Simon, 1898 Neotropical 4 (j_on|_i_p_e_s) iJJJ^jJa Simon, 1885 Malay Peninsula (micans_) and East Indies [^3 Total 37 1 Based on Roewer (1954) with additions from the Zoological Record through vol. 98, sect. 12, 1961. BRADY: LYNX SPIDERS OF NORTH AMERICA 435 when propcfly diagnosed, -will undoubtedly prove to have a distribution comparable to that of Oxyopes and Peiicetia. It is also possible that the large genus Oxyopes may be found to con- sist of several distinct groups each deserving generic status. SUPERFAMILV LVCOSOIDEA The oxyopids are grouped with the Agelenidae, Lycosidae, Pisauridae and Senoculidae in the superfamily Lycosoidea by most araneologists. The Oxyoi)idae, in common with most mem- bers of these families, po.ssess: eight eyes, three tarsal claws without claw tufts, three pairs of spinnerets, two lung books opening at the corners of the epigastric furrow, a single tracheal opening in front of the anterior spinnerets, and a rather large colulus. In addition, all members of this superfamily, with the exception of the Agelenidae, have the trochanters notched. The trochanters of pisaurids and lycosids are more deeply notched than in oxj^opids, while most agelenids do not have notches, although some do, according to V. D. Roth (per. comm.). The lynx spiders are a highly specialized group of the Lyco- soidea ; that is, they are probably more unlike the ancestral stock than any other family in this complex. The agelenids, lycosids and pisaurids are linked by intermediate forms, whereas it is difficult to find intermediates between the oxyopids and any of these three families. I am not familiar with the spiders of the family Senoculidae except by examination of preserved speci- mens. They also appear to be a very distinct group of the Lyco- soidea, but some authors place them near the Oxyopidae (Simon, 1898). On the basis of morphological characters and reported habits, I can see no close affinities between the Oxyopidae and Senoculidae. Although the oxyopids form a distinct line of evolu- tion, their affinities unmistakably lie with the lycosoids. Unlike most other representatives of the families of the Lyco- soidea, the Oxyopidae are most active during the day. Many species are found running swiftly or jumping with great agility among low shrubs and herbs. The North American oxyopids are easily recognized in the field by the presence of numerous large erect spines on the legs (Figs. 4, 49, 50, 121, 138) and by their quick darting movements and sudden leaps. The posterior legs are well developed, concomitant with their jumping ability. The habits of these spiders and their relatively keen eyesight have earned for them the name lynx spiders. Under the microscope one can readilj^ identify the lynx spiders 436 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY by their peculiar hexagonal eye arrangement (Figs. 1-3, 108-111, 136, 137). The eye arrangement and the spines on the legs most readily separate the oxyopids from all other families of spiders. In addition, the lynx spider fixes its egg ease to a twig or leaf and enmeshes it with a netAvork of silk, or suspends it from a small limb or branch with a guy-line. The female always stands guard over the egg case until the young emerge. The nearest counter- part to this type of maternal behavior is found in some pisaurids that construct a so-called nursery web and remain near the egg case until the young spiderlings appear. In addition to this behavioral similarity, some tropical pisaurids, such as Thanatid- ius, with long thin legs and many spines, resemble Peucctia and Tapinillus in general structure. Thanatidius also inhabits tall grass and herbaceous vegetation as do many of the oxyopids. For these reasons I think that the nearest living relatives of the lynx spiders are among the Pisauridae. BIOLOGY OF THE OXYOPIDAE The Oxyopidae are diurnal hunting spiders. Most of the lynx spiders move actively about in search of prey. However, they often pause and assume a characteristic prey-catching posture to await their victim. Hamataliwa lies very still waiting in ambush for its prey, as do many crab spiders. The great major- ity of oxyopids live in tall grass, low shrubs and herbaceous vegetation. A few {Hamataliwa) are evidently arboreal in habits and some appear to run over the bare ground. That relatively little is known concerning the biology of the Oxyopidae is due chiefly to the difficulty of observing these spiders in the field. Probably 95 per cent of the oxyopids col- lected are taken by sweeping; thus they are observed only when they appear in the sweep-net. Judging from their local abun- dance, the lynx spiders are among the major predators of insects occurring in low shrubs and herbaceous vegetation. Very few observations have been made on the feeding habits of the lynx spiders. Recent investigations by W. H. Whitcomb and asso- ciates (1963) have disclosed that the lynx spiders are important predators of crop-damaging insects. Oxyopes salticus, one of the most common spiders of the cotton fields in Arkansas, has been reported as the chief predator of the cotton boll worm. Peucctia viridans is also an important predator on insect pests of cotton fields. Although several species of Oxyopes have been recovered from the nest of the mud-dauber, Sccliphron cocmentarium, these BRADY : LYNX SPIDERS OF NORTH AMERICA 437 ox^-opids do not constitute a large part of the prey of this wasp. Among thousands of specimens of oxyopids examined during this investigation only very rarely was an egg case found. In several hundred vials containing Oxijopcs salticus, only two egg cases were discovered. These were roughly spherical and about 3.5 mm in diameter; one contained 55 spiderlings and the other 18-20 eggs, each a little less than 1 mm in diameter. The extreme rarity of oxyopid egg cases is probably due to the method of col- lecting the.se spiders. In sweeping the vegetation the spiders are dislodged, but the egg cases, firmly attached to the vegeta- tion, are not. Egg cases of Peucctia viridans, a much larger and more conspicuous lynx spider than Oxyopcs salticus, are en- countered more frequently. These egg sacs are rounded, from 12-25 mm in diameter, flattened on one side, and, except in the Southwest, have pointed projections on the surface. The eggs are about 1.5 mm in diameter. The number of eggs in an egg case is dependent on many factors and for that reason is ex- tremely variable. The contents of nine egg cases of Peucetia viridans ranged from 197 to 602 eggs. Often the chief factor in determining the number of eggs deposited is probably the size of the individual spider, larger spiders depositing more eggs than smaller ones of the same species. Peucctia viridans, the largest North American lynx spider, produces many more eggs than the much smaller species of Oxyopes. The North American lynx spiders evidently have one genera- tion per j^ear and probably construct only one egg case. The adults of several species of Oxyopcs appear first in late spring (May and early June) and are most abundant in July and Au- gust. Adult Peucetia appear later, in late July and August, and are most abundant in August and September. In general there seems to be a correlation between the size of the species and its date of maturity. Smaller species of Oxyopcs ajipear as adults in May, while Peucctia reaches maturitj^ in July. From the limited information and observations made, it appears that most lynx spiders over-winter in the egg case as embryos or first instar spiderlings ; however, in the extreme southern portions of their ranges there are probably several generations per year and adults may be found at any season. Although very few observations have been made of oxyopids ballooning, they undou])tedly employ this means of dispersal. Gliek (1939), in his study of the distribution of in.sects, spiders and mites in the air, reported 21 specimens of Oxyopcs and one 438 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY Peucetia taken from 200-3,000 feet (70-1000 m), most nearer the lower elevation. These 22 specimens were collected from August, 1926 to October, 1931, in the air over Tallulah, Louisiana. Suzuki (1952) reported that the chromosomes of five species of Oxyopes had been studied. All five species had 11 chromo- somes in the haploid state and an XO sex-determining mechan- ism. The XO-mechanism of the male (2N = 21), as well as the number of chromosomes, was similar to that found in the sub- family Misumeninae of the family Thomisidae. In one species of Peucetia studied by Suzuki there were 13 autosomes and 2 X-chromosomes of different size. The male of Peucetia (2N = 28) was similar in these characters to many Philodromus species, as well as to most species of Lycosidae that were studied. Since the oxyopids are diurnal and possess relatively keen sight, their courtship behavior probably plays an important role as a primary isolating mechanism. Mating in the Oxyopidae, however, has been observed onlj^ rarely, and the comparative aspects of this behavior are unknown. Gerhardt (1928, 1933) has observed courtship behavior in two European lynx spiders, Oxyopes ramosus and Oxyopes heterophthalmus. Although males of 0. heterophthalmus readily displayed, Gerhardt (1933) suc- ceeded in mating these spiders in captivity only once. Copula- tion is in the modified running-spider position (see Kaston, 1948, fig. 2006). The male approaches the female from in front and climbs on top. The venter of the female is slightly turned to- ward one side, allowing insertion of the palpus. In 0. heteroph- thalmus the large tibial process (Fig. 101) of the male is used to orient the palpus. The male swings itself around 180° so that its body is in the same direction as the female's. No observations of the mating behavior of North American oxyopids have been recorded. A comparison of courtship behavior in the lynx spiders would, undoubtedly, prove most informative. ACKNOWLEDGMENTS I am greatly indebted to Dr. H. W. Levi of the Museum of Comparative Zoology, who, by his helpful advice, useful sug- gestions and constant encouragement, has made the preparation of this paper a much easier task. The collections of the Museum of Comparative Zoology and the library of this institution were invaluable to me during this investigation. I wish to thank sincerely Dr. W. J. Gertsch who placed the very large collec- tions of the American Museum of Natural History at my dis- posal, thus making possible a tlioi'ougli and comi)lete analysis of HKADY : LYNX SPIDERS OF NORTH AMERICA 439 many species. Dr. Gertscli was kind enough to include specimens that he liad previously recognized as new species and they are described in this study -with his permission. During the course of this investigation I spent several weeks at the British Museum (Natural History) where I examined the types of 0. P.- and F. 0. P.-Cambridge. Photographs were also made of the plates of John Abbot (1792) which are de- posited in the library of that museum. I am grateful to Dr. G. Owen Evans, Mr. Douglas Clark and Mr. Keith Hyatt for mak- ing my visit to the British Museum (Natural History) a most pleasant and profitable one. Professor M. Vachon supplied photographs of the Bosc plates, which are kept in the library of the Museum National d'Histoire Naturelle, Paris. A travel grant provided by the Evolutionary Biology Com- mittee of the Biology Department of Harvard University made the trip to the British Museum (Natural History) possible. I wish to thank the Biology Department of Harvard University also for financial aid on several collecting trips into the southern United States. Collections of Mrs. D. L. Frizzell (Dr. H. Exline) and Mr. J. A. Beatty aided me in this study considerably and 1 appre- ciate their loans in behalf of this investigation. To the following persons and their respective institutions I wish to express my thanks for supplying regional collections that provided a more complete picture of the geographical dis- tribution of certain species: Dr. H. K. Wallace, University of Florida ; Mr. Vincent D. Roth, Southwestern Research Station ; Dr. F. G. Werner, University of Arizona ; Dr. George Byers, University of Kansas; Miss Beatrice Vogel, University of Colo- rado Museum; and Dr. C. A. Triplehorn, Ohio State University. A special debt of gratitude is owed to jMrs. Lorna Levi for critically examining and editing the rough draft of this manu- script. Miss Susan Koelle mapped the species distributions and constructed the Dice-Leraas diagrams. National Institutes of Health grant AI-01944 helped defray some expenses involved in this study. WALCKENAERIAN NAMES Walckenaer (1838) in Volume I of "Histoire Naturelle des Insectes Apteres, ' ' named and described, from the Georgia region of North America, three new species of oxyopids in the genus Sphasus, a genus since synonymized with Oxyopes. In addition. 440 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY Walckenaer (1838, 1841) named and described three species of Clastes, placed in the family Sparassidae, from the Georgia re- gion. The six names that concern us in this paper were applied to the original drawings of the unique manuscript of John Ab- bot (1792). Since they were rediscovered in the British Museum (Natural History) by McCook (1888), the Abbot drawings have been considered the types of the Walckenaerian names by most North American araneologists. They had been used with some reservation, however, until Chamberlin and Ivie (1944) attempted "to determine, as far as possible from avail- able evidence, the proper application of the names based by Walckenaer upon Abbot's drawings of the spiders of Georgia." In their paper, Chamberlin and Ivie placed in synonymy manj- well-established names that had been used for North American spiders. Involved are 282 names that Walckenaer applied to drawings made by Abbot. These must be considered when re- vising almost any family of North American spiders. I agree with Levi and Levi (1961) that these names can only be given proper treatment by the investigator who has made a thorough and intensive taxonomic study of the spider genera in question. Unfortunately, Walckenaer made many mistakes in the iden- tification of the Abbot drawings, and Chamberlin and Ivie have made some errors in their all-inclusive determinations of the Abbot drawings. A few of these errors are pointed out by Levi and Levi (1961) and this investigation has disclosed several more. Of the three species of Sphas^(^ (= Oxyopes) described by Walckenaer, only one appears to be an oxyopid. The disposition of the three is as follows : Sphasus arcuatus Walckenaer (Abbot numbers 322, 323) is not an Oxyopes, as it was designated ])y Chambei-lin and Ivie (1944), but probably belongs in the theridiid genus SpinfJiarus. There are no spines on the legs of this spider as figured by Ab- bot, an important characteristic of all oxyopids; the color pat- tern is not like that of any oxyopid that I have seen, but is sim- ilar to that of Spintha7-i(s fiavidus (Hentz) ; and the eye ar- rangement, a very important character, is not as in the Oxyo- pidae. Body form, coloration, and relative length of the legs is like that in Spintharus fiavidus (Hentz). Sphasus vittatus Walckenaer (Abbot number 369) is obvi- ously not an oxyopid. Tliis spider was placed in the genus Castianeira of the family Clubionidae by Chamberlin and Ivie BRADY : LYNX SPIDERS OF NORTH AMERICA 441 (1944). Judging from the original figure of Abbot, that is where it probably belongs. However, no species is known to which the description and figure can be applied. Sphasus Janccolatus AValckenaer (Abbot number 42) is an oxyopid. Chaml)erlin and Ivie (1944) described a species of Oxijopcs under this name. Although they designated a neotype, it has no validity since the holotype, namely Abbot's figure 42, is still extant. The neotype has since been misplaced or lost and was not available for examination ; thus it cannot be com- pared with Abbot's original figure. We have only the figure of Abbot to guide us, and the dorsal view, showing the color pat- tern and eye arrangement, is not sufficient for diagnosis in this case. Tlie colored drawing of AbI)ot, much like that of Oxyopes scalaris Hentz, may also be 0. aglossus Chamberlin or 0. ac- leistus Chamberlin. Chamberlin and Ivie (1944), however, con- sidered these three species distinct from 0. lanceolatua. Oxyopes lanceolatus has been perpetuated in the catalogues of Marx (1890), Petrunkevitch (1911), Roewer (1954), and Bonnet (1958). It has not otherwise been used in the literature except by Chamberlin and Ivie (1944). Since the name 0. lanceolatus might be applied to at least four distinct species, I think that it is best considered a nomen duhium. Three names proposed by AValckenaer (1838, 1841), Clastes ahboti (Abbot number 401), C. roseiis (Abbot number 411), and C. viridis (Abbot number 406), were recognized as the same species by Chamberlin and Ivie (1944). They applied the name Peucetia ahhoti (Walckenaer) to this large green lynx spider of the southeastern United States. The name Peucetia viridans (Hentz) had been used for this species for 100 years prior to the change by Chamberlin and Ivie (1944). Hentz 's name ac- tually has priority, having been used first in 1832, six years before "Walckenaer 's publication. Walckenaer previously (1805) described and named another oxyopid for a drawing appearing in the unique manuscript of Bosc (1800) on the spiders of the Carolinas. This manu- script is deposited in the Paris Museum. The drawing (Bosc, pi. 4, fig. 1) was designated Aranea fossana by Bosc (1800), and its description was published by Walckenaer (1805) who called it SpJiasus fossanus. Judging by Bosc's drawing and the description of Walckenaer, this species is Peucetia viridans (Hentz). Oxyopa fossana was listed by Simon (1864) and the name Oxyopes fossanus has been perpetuated in the catalogues 442 BULLETIN : MUSEUM OP COMPARATIVE ZOOLOGY of Marx (1890), Petriinkevitch (1911), Roewer (1954) and Bon- net (1958). The name has never been applied or used in any manner to designate a species of Oxyopidae. It is here con- sidered a nomen ohlitum. In summary, the following' dispositions have been made of the Walckenaerian names: SpJiasus arcuatus is probably Spin- tharus flavidus Hentz ; Sphasus vittatus is probably a Castian- eira; Sphasus lanceolatiis is a species of Oxyopes, but there is some doubt as to which one; Clastes ahhoti, C. roseus, and C. virklis are Peucetia viridans (Hentz). Spliasns fossanus is probably Peucetia viridans (Hentz), and is considered a nomen ohlitum. METHODS Measurements. Two sets of oculars with accompanying grids were used in combination with low and high power objectives for making measurements. The higher power combination was used in measuring the width of the eye rows and was determined to be accurate to 0.0125 mm or one-tenth unit of the micrometer grid. The lower power combination was used to measure the body dimensions and leg lengths and was determined to be ac- curate to 0.1 mm or one-tenth unit of the micrometer grid. A measurement when retaken was nearly always read within one unit of the original measurement with either of the above mi- crometer grids, e.g. an original measurement of 7.5 micrometer units when retaken yielded 7.4-7.6 units. In all cases the great- est dimension of the structure was recorded, e.g. patella-tibia length was measured as the greatest distance from a line tangent to the most proximal part of the patella to a line tangent to the most distal part of the tibia. All available specimens of sparsely collected species were measured and a set of 30 specimens of each sex was measured for those species abundantly repre- sented in collections. A series of 15 measurements involving various components of the spider was made for each specimen. The range and mean of the total length for each species is given in its description and the relative length of the legs is also given. Other diag- nostic measurements are recorded for Oxyopes in Table II and for Hamataliwa and Peucetia in Table III. The segments of leg I were measured from the prolateral aspect, as was patella- tibia II. The patellae-tibiae of legs III and IV were measured from their retrolateral aspect. BRADY : LYNX SPIDERS OF NORTH AMERICA 443 Figures and color descriptions. The color deserij)tions and illustrations are based on fresh alcoholic specimens in most cases and represent these species as they appear in nature. Tlie genus Peucctia is an exception. Tliis spider is bright green in life, but the color Avashes out rapidly in alcohol. Therefore, an at- tempt was made to describe both preserved and living animals of Peucetia. Color descriptions and illustrations Avere made under low power (15X) of a dissecting microscope, with the spider illnm- inated by a microscope lamp. The well-marked specimens are those in which the hairs forming the color pattern have not been rubbed off. Where variation is great, the color pattern or pat- terns representative of the greatest number of specimens is described, with significant differences noted. Well-preserved alcoholic specimens of Oxyopes and Hamataliiva are very sim- ilar in coloration to the living spider. The most fre(iuent dif- ferences are caused by shrinking in alcohol, Avhich disrupts the pattern on the abdomen, and rubbing off of the spatulate ap- pressed hairs that make up much of the color pattern in these two genera. For each species the face view as well as the dorsal view of a male and female (Avhen available) was drawn, with additional drawings to indicate variation. At least two drawings of the female genitalia Avere made for each species : a A^entral external view of the epigynum after all the hair had been removed (often revealing some internal structure through the integument), and a dorsal internal vicAV Avith the separated genitalia submerged in clove oil for clearing. The female genitalia of all species of Oxyopes and IlomataUwa are draAvn to the same scale. Peucetia is draAvn on a smaller scale. The scales are indicated on the plates. Two views of the male palpi Avere draAvn for each species : a ventral a'Icav and a retrolateral view. The left palpi of the males were drawn after gently scraping them free of hair to reveal the palpal sclerites and the tibial and patellar apophyses. No attempt Avas made to indicate hirsuteness or spination in these drawings. All palpi of Oxyopes and Hamataliwa are draAvn to the same scale. Peucetia palpi are draAvn on a smaller scale. That area referred to as the face is, in oxyopids, the anterior vertical plane of the head as seen from in front (Figs. 1 and 5). It comprises the frontal aspect of the carapace and includes the front of the chelicerae. 444 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY Records. Complete records for all the specimens examined during this investigation are listed in the Doctoral Dissertation. Copies of the dissertation are deposited in the library of the Biological Laboratories and in Widener Library, Harvard Uni- versity. Locality records are listed geographically by states in a sequence from north to south and from east to west. Coun- ties are listed alphabetically under states, cities and towns alphabetically under counties. Counties only are listed when a particular species is abundantly represented and obviously common in a given geographic area. For less well collected species full information is provided. The number of specimens collected at each locality is indicated, with thq lower case "o" representing immature specimens in the same manner that the $ and 9 signs represent the mature sexes. Collectors' initials, following the localities, are listed in a separate index at the rear of this paper. Occasional collectors are given by name. TAXONOMIC SECTION Family OXYOPIDAE Thorell Oxyopidae Thorell, 1870, Nova Aeta, Eeg. Soe. Sci. Uppsala, Stockholm, 7(3):188, 196. Type-genus Oxyopes^ Latreille, 1804. Characteristics. Eyes : Anterior row recurved, except in some Hamataliwa. Anterior median eyes (AME) smallest, much smaller than the anterior lateral eyes (ALE). Posterior row procurved {exce-pt in Tapiiiillus) . Posterior median eyes (PME) equal in size to posterior lateral eyes (PLB) ; both pairs larger than the AME, but smaller than the ALE, which are the largest (Figs. 1-3, 108-111, 136, 137). The AME row is much the smallest in width, the ALE row is always larger than the AME row, and subequal to the PME row, except in Peucetia, Tapinil- lus, and some Hamataliwa (compare Table II with Table III). The PLE row is the widest. The chelicerae are very long and tapering at the distal end, and the fangs are short. The base of the fang occupies most of the distal end of the chelicera. The cheliceral margins are short and armed with one tooth on each side of the anterior and posterior margins (Oxyopes and Hamataliwa) or without teeth {Peucetia and Tapinillus) . The boss on the anterior lateral 3 According to Thorell (18(59) Oi^yopvs is derived from the Greelj and means sharp-eyed. BRADY: LYNX SPIDERS OF NORTH AMERICA 445 face of tlie cliolicera is not so proiuiuciit as in agolenitls, pisaur- ids and lycosids. Tlie articular sockets of the chelicerae at the lower marfjins of the face are heavily selerotized and dai-kly j)i