part 4] CUMBRIAN HORIZONS OF COMLET. 367 



LATOrCHELLA (?) STRIATA, Sp. 110V. (PI. XXIV, figs. 43 & 44.) 



Type-specimen [2655], other specimens [2659, 2661, 2662]. 



Diagnosis. — Shell coiled so as to make about three-quarters of 

 a complete whorl ; aperture an elongate egg-shaped oval, narrow- 

 ing towards the dorsum ; surface showing numerous, fine, impressed 

 radiating strise which strengthen as they approach the aperture, 

 and of which some four or six are still more strongly marked along 

 the dorsum. Dorsum narrowly rounded, hut not keeled ; no con- 

 centric lines of growth visible in the specimens. 



Dimensions of largest specimen. — Apertural diameters = about 

 6x2 mm. ; total length =about 6 mm. ; height=5 mm. 



This species is proportionately higher and narrower than L. 

 costata, and the whorls are distinctly separated one from the other. 



Localities and horizo n . — Comley, Lower Cambrian , from the 

 Protolenus Limestone, horizon Ac 3 ; also one specimen from the 

 Hyolithus Limestone of Woodlands Quarry, Hartshill, Nuneaton 

 [Birmingham University Collection]. 



VIII. The Comley Ostracoda. 

 Leperditia. Rouault. 



Leperditia (?) le^tiformis, sp. nov. (PI. XXIV, figs. 46 a- 

 46 c.) 



Type-specimen [Birmingham University Collection]. Three 

 other specimens known. 



Diagnosis. — General outline bean-shaped ; anterior end shortly 

 truncate ; dorsal border gently convex for about two-thirds of the 

 total length, then bending more rapidly and passing to the posterior 

 rounded end in a line that is almost straight ; ventral border one 

 long fairly-regular curve from the truncate anterior to the posterior 

 end ; surfaces of both valves regularly convex, except near the 

 anterior end, where there is a short ill-defined depression passing 

 obliquely towards the ventral border ; test thin, corneous, having 

 the surface marked by a network of impressed lines, the interspaces 

 being convex, and more or less elongate and parallel with the 

 border. 



Dimensions. — Length=ll - 5 mm.; depth = 7 mm. ; thickness 

 of the two valves together=4 mm. 



The general aspect of the species recalls that of L. (?) clermatoides 

 Walcott, 1 which chiefly differs in having a very thin membranous 

 and punctate test ; that species has also a minute scar towards the 

 posterior end, and a rather differently curved border. 



In the type-specimen the two valves are in their natural 

 position. 



Locality and horizon. — Comlej r , Lower Cambrian; from the 

 Olenellus Limestone, horizon Ac 2 . 



1 1890, p. 626 & pi. lxxx, figs. 1-1 a. 



