Mr. E. A. Smith on the Genus Pythiua. 227 



only species which it resembles in this respect bcin;^, I 

 believe, G. j^i^sil/us of Meinert, from North Africa. It is 

 undoubtedly very closely allied to the above-described G. 

 antipod(wi, but differs in having a smaller number of legs, 

 in being broader in the liead, &.c. 



EXPLANATION OF PLATE XII. 



Fiff. 1. Jlenia atheyiarum, sp. n. Head from bolow. 



I'iff. 2. Geophi/us Grantii, sp. n. Anal soiiiito from below. 



Fig. 3. Gcophilm challcnr/eri, sp. n. Head from above. 



Fiy. 3 a. Ditto. Head from below. 



Fiy. 4. Geophiliis parthorum, sp. n. Head from above. 



Fig. 4 a. Ditto. Anal somite from below. 



Fig. 5. Geophilus si/dneyetms, sp. n. Head from above. 



Fig. 5 a. Ditto. Head from below. 



Fig. 5 b. Ditto. Anal somite from below. 



Fig. 6. Geophilus laticeps, sp. n. Head from above. 



Fig. G a. Ditto. Head from below. 



Fig. 7. Geophilus niorhostis (Hutton). Head from above. 



Fig. 7 a. Ditto. Anal somite from below. 



Fig. 8. Geophilus antipodum, sp. n. Anal somite from below, 



Fig. 9. Geophilus Huttoni, sp. n Head from above. 



Fig. 9 a. Ditto. Head from below. 



Fig, 9b. Ditto. Anal somite from above. 



Fig, 10. Geophilus provocatoi; sp. n. Head from above. 



Fig. 10 a. Ditto. Head from below. 



Fig. 10 b. Ditto. Anal somite from below. 



Fig. 11. Geophilus alacer, sp. n. Head from below. 



Fig. 11 a. Ditto. Anal somite from below. 



Fig. 12. Crgptops atlantis, Pocock. Anal leg; from the side. 



XXVI. — Remarks upon the Genus Pytliina of Hinds and the 

 Species which have been referred to it, upon Mysella of 

 Angnsj and the Description of a neio Species of Mylitta. 

 By Edgar A. Smith. 



[Plate XIH. A.] 



(rt) On Pttrina. 



The genus Pythina was establislied by Hinds in 1844 for a 

 small triangular bivalved mollusk collected at New Ireland 

 during the voyage of the ' Sulphur,' which is distinguished by 

 a very peculiar kind of surface-ornamentation or sculpture, 

 namely ribs or folds which extend from each end of tlie valves 

 in an upward direction, meeting and divaricating at the 



15* 



