Mr. F. P. Marrat on a new Species q/ Marginella. 141 



extended, cup-shaped head, with curved sh.aft. (This curved 

 kind of shaft is so common and so remarkable that it also ia 

 very characteristic of Gcodites hahlonensis, if not deserving of 

 a different specific denomination.) Fig. G8. The same as the 

 last, witli quadrifid head, furcated irregularly ; variety. 



Fici. 00. Ilexternate head; stout spicule. 



Fiy. 70. Ternate expanded head ; large spicule. SteUettites hnldonensis. 

 This spicule shows a very common occurrence in the deposit, 

 viz. the bare extension of the axial canal («), in solid petrifaction, 

 without the walls of the spicule. 



Fif/. 71. Ternate head; arms straight, pointed, expanded laterally and 

 forwards ; shaft and arms very much alike in many varieties ; 

 numerous, of many sizes. Dercitcs haldonensis. 



Fig. 72. Quaternate head, contracted, with long shaft; lateral view. 

 Gomphites jjarviceps. 



Fie/. 7.3. The same, end view. 



Fiij. 74. Lateral view of Gomphites Parjittii. 



Fiy, 75. Portion of long shaft, to show the enlarged state of the axial 

 canal, which is frequently present in these fossil spicules : 

 a, wall of spicule, very thin ; h b, axial canal, much enlarged ; 

 c c, grains of sand in it ; d, end of spicule in it. 



Fir/. 76. Specimen of the large, fusiform, smooth, slightly curved, acerate 

 spicule common in the deposit : a a, the pointed ends. This 

 Ivind of spicuFe is very abundant, entire and fragmentary, of all 

 sizes. The figure represents the average largest size, viz. about 

 l-5th of an inch long. The limits of the plate are not sufficient 

 to allow of the spicule being represented in its entire length, 

 and therefore the middle portion and two ends only have been 

 delineated. The same remarks apply to the following spicule. 



Fi(/. 77. Large fusiform acuate spicule, average large size, about l-9th of 

 an inch long. 



Fiff. 78. Smaller acuate spicule. 



Fiff. 79. Large contort bihamate spicule, Esperites giganteus. 



XV. — On a New Species o/Marginellayvwn South Africa. 

 By F. "p. Marrat. 



[Plate XI. fig. 13.] 

 Marginella Keenii, Marrat, n. sp. 



Sliell conically ovate ; spire short ; whorls four, rounded, blunt 

 at the apex ; colour orange-buff, somewhat translucent ; 

 columella with four sharply raised plaits ; outer lip thick- 

 ened, smooth within. 



Hah. South Africa. 



I have named this shell after my friend Mr. Keen, of Edge 

 Lane, Liverpool, to whom the specimens (six in number) be- 

 long, and whose collection of Marginellce is considered to be 

 the finest in England. 



100 Edge Lane, Liverpool. 



