253 F. R. Cowper Reed — Salter's Undescribed Species. 



Salter says of this form that it is " squarer and more ovate than 

 the kindred Caradoo forms." There are four specimens in the 

 "Woodwardian Museum, and Salter based his species on two of them 

 (a 979) consisting of a complete internal cast of both valves and 

 an external cast of the upper portion of the shell. All were found 

 in the Lower Llandovery Beds (Upper Bala of Salter) of Sefin 

 Llettyrhyddod, Llandovery. 



Diagnosis. — Shell equivalve, inequilateral, transversely subovate, 

 narrowing and subtruncate posteriorly, subcompressed. Beaks obtuse, 

 moderate, near anterior end, with small impressed lunule in front below 

 them. Hinge straight, about two-thirds width of shell. Anterior 

 portion of shell convex; posterior portion slightly flattened, com- 

 pressed. Anterior end broadly rounded ; posterior end narrower, 

 more pointed, angulated between ridges. Ventral margin regular, 

 subparallel to dorsal. Two faint low diverging ridges run obliquely 

 backwards over posterior slope of valves to posterior end of ventral 

 margin, but are almost indistinguishable near the beak. Hinge 

 area behind beaks narrow, lanceolate. Ligament external, in groove. 

 Hinge-line edentulous? Pallial line simple, no sinus. Posterior 

 adductor scar well marked, about half-way between beak and posterior 

 extremity. Anterior scar faint. Surface of valves marked by faint 

 concentric growth-lines. 



Measurements. mm. 



Length ... ... ... ... ... 15 



Width ... ... ... ... ... 24 



Thickness ... ... ... ... ... 8 



Eemaeks. — The characters of the hinge and absence of the typical 

 teeth would alone be sufficient to remove this species from the genus 

 Ctenodonta ; and it appears to belong to the genus Orihonota. 



Orthonota solenoides (Sow.) ^ bears a distant resemblance, but is 

 relatively more transverse, and the posterior ridges are wanting. 



ACTINOZOA. 



Heliolites ojiispiTOSA, Salter. (PI. XVI, Figs. 6, 7.) 



1873. Heliolites cmspitosa, Salter : Cat. Camb. Sil. Foss. AVoodw. Mus., 



p. 104 {a 343). 

 1888. Heliolites cmspitosa, Etheridge : Cat. Brit. Foss., pt. i (Palteoz.), p. 20. 

 1891. Heliolites cmspitosa. Woods : Cat. Type Foss. Woodw. Mus., p. 20. 



The three original specimens (a 343) come from the Wenlock 

 Limestone of Dudley and belong to the Fletcher Collection, The 

 species is not uncommon there, and we have numerous specimens 

 from the same locality. Salter (op. cit. supra) describes it as 

 " something like fl". Grnyi, but cells approximate; shallow pits, not 

 raised." One of the original specimens is a fine and almost perfect 

 corallum. 



Diagnosis. — Corallum ramose, but not diffuse, consisting of several 

 subparallel, irregularly rounded or lobate, stout branches, increasing 

 in thickness from the base, and bearing calices over their whole 

 surface. Larger oorallites small, very numerous, approximate, 



* Murchison Siluria, .5th ed., 1872, pi. xsiii, fig. 9. 



