72 



Affinities. — It is a little difficult to know where the proposed 

 new genus should be placed. Dr. Pilsbry points out (Man. 

 Con., vol. xiv., p. 312) that the genera Placiphorella and 

 Mopalia are separted from the Plaxiphora in that the tail 

 valve of the latter is unslit, with the additional character in 

 the former of "peculiar girdle bristles" ; now the species under 

 review has the tail valve unslit, as in Plaxiphora, but has, on 

 the other hand, a striking character in its "peculiar girdle 

 bristles." 



I pointed out in my paper on Loricella some points of 

 similarity between that genus and Placiphorella. Since 

 writing my description and preparing figures of the new 

 features noted in P. matthewsi, I have noticed Messrs. Iredale 

 and May's remarks on this species in their valuable paper 

 (Proc. Mai. Soc, vol. xii., pts. ii. and iii., Nov., 1916, 

 p. 101), where they say, referring to P. matthewsi, "Receipt 

 of well-preserved specimens from Tasmania shows that the 

 species has no close relationship with Frembleya, the animal 

 being obviously different. This is now being investigated, 

 but in the meanwhile a nearer ally from a superficial 

 examination might be Loricella." 



The outward appearance of the tail valve certainly 

 suggests Loricella, and the strange girdle bristles do still more 

 so, but the unslit tail valve and the non-emarginate girdle 

 show a closer affinity with the Mopaliidae, Pils. For the 

 present I think we must leave the suggested new genus under 

 Plisbry's family Mopaliidae, but future research may necessi- 

 tate some revision of this family and that of the Liolophurinae. 



Rhyssoplax torrianus, H. and H., var. klemi, nov. 



Amongst the specimens of the above chiton collected by 

 Dr. Torr and Mr. Klem at Corny Point, Yorke Peninsula, is 

 a rather striking variant from the normal form. The usual 

 deep, longitudinal sulci, edged with black, which traverse the 

 pleural areas, are reduced in this specimen on some valves to 

 three, on others four on each side, and the similar black 

 dashes on the dorsal area vary from one to two on each side. 

 Again, the sulci are hardly developed at all, and the black 

 lines are most of them mere dashes on the posterior portion 

 only, of the pleural areas. The general effect is rather striking, 

 the shell looking decidedly bare of markings and sculpture. 

 The specimen is in Dr. Torr's collection. 



This variety appears sufficiently distinctive to deserve a 

 name, and therefore I suggest that it be known as var. klemi, 

 after the gentleman who was co-worker with Dr. Torr at the 

 time it was collected. 



