394 PROCEEDINGS OP THE ACADEMY OF 



lo modesta. Testa Isevi, conica, virido-cornea. ; spira regulariter conica,; 

 suturis impressis; anfractibus novenis, planulatis, in medio angulatis; aper- 

 tura parva, regulariter rhomboidea; labro acuto et sinuoso ; columella alba 

 et valle contorta,; canali curta. et effusa. 



Hab. Tennessee River, Alabama. Wm. Spillman, M. D. 



Io Spillmanii. Testa laevi, attenuato-conica, pallido-cornea ; spira regulari- 

 ter conica, superne striata; suturis leviter impressis; anfractibus instar deuis, 

 planulatis, in medio obtuse angulatis ; apertura parva, rhomboidea ; labro 

 acuto et sinuoso; columella alba et valde contorta; canali curta et subeffusa. 



Hab. Tennessee River, Alabama? Wm. Spillman, M. D. 



To gracilis. Testa lasvi, conica, pallido-purpurea ; spira regulariter conica ; 

 suturis regulariter impressis; anfractibus instar novenis, planulatis, in medio 

 angulatis; apertura parviuscula, rhomboidea; labro acuto et sinuoso; colu- 

 mella pallido-purpurea, valde contorta et deflecta; canali curta et late effusa. 



JJab. Coosa River, Alabama. Wm. Spillman, M. D. 



Io viriddla. Testa Isevi, cylindrico-conoidea, virente ; spira subelevata ; 

 suturis parura impressis; anfractibus instar novenis, planulatis, in medio ob- 

 tuse angulatis ; apertura parviuscula, rhomboidea ; labro acuto, sinuoso ; colu- 

 mella ad basim purpurea, parum contorta; canali curta et dilatata. 



Ilab. Coosa River, Alabama. Wm. Spillman, M. D. 



A Revision of the specie3 of BACULITES, described in Dr. Morton's " Synopsis 

 of the Cretaceous Group of the United States." 



BY W. M. GABB. 



In the above mentioned work, Dr. Morton described six species of Baculites, 

 two of which (B. compressus and B. o v a t u s) had been previously 

 characterized and named by Say. All of these species were published with 

 very short and meagre descriptions, although the illustrations were pretty ac- 

 curate ; the original specimens, however, are still preserved in the Museum of 

 the Academy, and from them I have been enabled to arrive at tolerably satis- 

 factory results, in the determination of the true relations of the several forms. 



Mr. Say's species have been elaborately described and figured by Messrs. 

 Hall and Meek in the Transactions of the American Academy of Arts and 

 Sciences of Boston, vol. v. 2d series. I shall therefore not refer to them 

 again, further than to say that they are very distinct from the species with 

 which I am now occupied. 



Baculites labyrinthicus Morton, Syn. p. 44, pi. 13, fig. 10. 



This is probably the only form among those described by Dr. Morton which 

 is entitled to rank as a valid species, unless B. columna should prove to 

 be distinct from B. carinatus = B. anceps. 



Sp. char. B. testa compressiuscula, tuberculis serie duplici positis, dorso 

 subacuto, ventre plana, apertura incognita ; septis lobatis. 



Shell subcompressed, section rounded, pentagonal ; dorsum acute ; ventral 

 side flattened, bounded by a row of subacute nodes on each side ; midway be- 

 tween each of these nodes and the dorsum is another one of about the same 

 size. Longitudinally between the nodes, the surface is slightly excavated; 

 laterally, the excavation is almost invisible. Septum ; dorsal lobe broader 

 than the dorsal saddle, not so long as the superior lateral lobe, deeply exca- 

 vated by a broad sinus in the middle, on each side of which extends a branch 

 which is separated into one large and one small fork, the inner or largest one 

 being trifurcate, above the outer one there is another smaller process, dorsal 

 saddle divided for more than half its length by a long serrate process, each 



[Deo. 



