Baker — Critical Notes on the Muricidae. 373 



quently confounded with tribulus, ternispina and rarispina. 

 It may be considered a variety of the first-named species, 

 characterized by dark colored spines shading from black into 

 blue. This is the only species of the subgenus which has 

 these peculiarly colored spines. This fact will at once dis- 

 tinguish it from the nearly related species. 



Murex tribulus var. aduncospinosus Beck. 



Murex aduncospinosus Beck., Reeve, Conch. Icon., fig. 93. 



I recently had the pleasure of examining a specimen of this 

 species, and am led thereby to make the above disposition of 

 it. The spines are quite curved and the whole shell is of a 

 much darker color than in the typical tribulus. Sowerby in 

 Conchological Illustrations gives a very good figure (fig. 68). 

 The species is from the Red Sea. 



Murex tribulus var. carbonnieri, Jousseaume. 



Murex carbonnieri Jouss., Le Naturaliste, No. 44, p. 349. Nouvelles 

 Archives du Museum, plate x, fig. 1. 



This form will stand as a variety of tribulus characterized 

 by chestnut spotted spiral bands. I have seen a large num- 

 ber of specimens of this variety, and when perfect it is a 

 very handsome shell. The largest specimen seen by me 

 measured a little over three inches in length. 



Murex acanthodes, Watson. 



Murex acanthodes, Watson, Jour. Linn. Soc. London, p. 599, 1883. Chal- 

 lenger Report, Gastropoda, p. 151, pi. x, fig. 1. 



The specimen from which this was described is a juvenile 

 form, and I am strongly inclined to consider it the young of 

 Murex tribulus or some of its varieties. I have seen juvenile 

 specimens of tribulus which would answer to the description 

 of acanthodes. That it is a young shell is evident from its size 

 (alt. 1.8 in., diam. 0.6 in., aperture alt. 1.5 in. [excludiug 

 the canal 0.38 in.], diam. 0.27 in.), which is about that of 

 some small specimens of tribulus that I have seen. It was 

 dredged off Cape York, Australia, and Albany Island, in 3 

 to 12 fathoms. It is said by its describer to resemble Mac- 

 gillivrayi, aduncospinosus and Cabritii. 



