348 ROBERT TRACY JACKSON ON ECHINI. 



area E of the photographic figure (Plate 46, fig. 5). In area A ventrally, the initial plate of 

 column 6 is seen as a pentagon with a heptagon on its left ventral border. Ambulacral and 

 interambulacral plates alike bear small secondary tubercles with some minute tubercles between 

 them. Many small, slender, tapering spines up to about 3 mm. in length are borne on both 

 ambulacral and interambulacral plates (Plate 46, fig. 6). The dorsal part of the test is quite 

 unknown. I am indebted to Dr. Kitchin of the Museum of Practical Geology for the excellent 

 photograph of this species, which he kindly had taken for me by Mr. J. W. Tutcher. 



Lower Carboniferous, Clitheroe, Lancashire, holotype and only known specimen, Museum 

 of Practical Geology, London, no. 6,576. 



*Lovenechinus septies sp. nov. 

 Text-fig. 17, p. 59; Plate 44, figs. G, 7; Plate 45, figs. 1-6. 



The test is small, spheroidal, with remarkably perfect detail in the type, but crushed. 

 Width of the ambulacra at the mid-zone 8.5 mm., of the interambulacra at the same zone 18 mm. 

 Diameter in the neighborhood of 50 mm., but from the crushing it cannot be very closely stated. 



Ambulacra at the mid-zone and throughout most of the areas with four columns of plates, 

 wide occluded and narrow demi-plates in each half-area (Plate 45, figs. 1, 3). The occluded 

 plates laterally fit into the inner angles of the demi-plates, but with serrate, not tongue-like 

 extensions (as in L. missouriensis, Plate 42, fig. 2). Pore-pairs are biserial, situated in the 

 outer portion of each ambulacral plate. The ambulacral plates bevel over the adradials, and 

 the occluded plates rise in a high arch which is formed by the median thickening of these plates 

 (Plate 45, fig. 5). Ambulacral plates ventrally and dorsally are primaries, as later described 

 in detail. Interambulacra at the mid-zone are wide, with six columns of plates, but a seventh 

 appears dorsally in each area (Plate 45, fig. 1). The adambulacrals are pentagonal, others 

 hexagonal as usual. Two interambulacral plates are in the basicoronal row in most area, 1 --, 

 above which additional columns appear as usual in the family, as later described in detail. 

 Small secondary tubercles occur alike on ambulacral and interambulacral plates, but no spines 

 are preserved. Dorsally, the apical disc is crushed in, but can be made out in part. Oculars 

 are insert, imperforate, and adorally cover the ambulacra and laterally in part the interambul- 

 acra on either side. Genitals are high, wide, with two and probably more pores each. 



This species differs from others of the genus in having more columns of interambulacral 

 plates ; also the contact of occluded and demi-plates differs from that of other species excepting 

 L. mutatus, where the interlocking of these plates is closely similar. The holotype is in Mr. 

 Frank Springer's collection and was received by him from Professor G. Hambach of St. Louis, 

 Missouri. 



Warsaw Group, Lower Carboniferous, Boonville, Missouri; holotype in F. Springer's 



