114 MONODONTA. 



Trochus sauciatus KOCH in PHILIPPI, Abbild., i, Trochus, t. 5,f. 

 7 (1845). PHILIPPI, Conchyl. Cab., p. 201, t. 30, f. 5. T. inde- 

 corus PHILIPPI, Conchyl. Cab., p. 143, t. 24, f. 5. T. listeri WOOD, 

 Ind. Test, suppl., t. 5, f. 8 (no description). T. colubrinus GOULD, 

 Proe. Bost. Soc. N. H., iii, p. 107 (1849) and Expl Exped. Shells, 

 p. 183, f. 223. WATSON, Challenger Moll., p. 65. I 7 , sagittiferns 

 HIDAGO, Mol. de Espana, t. 60, f. 2-7 (not of Lamarck). T. 

 citrinus PHILIPPI, Conchyl, Cab., p. 290, t. 42, f. 14. FISCHER, Coq. 

 Viv., p. 262, t 88, f. 1. (? T. citrinus Gmelin.) 



PI. 24, figs. 92, 93 represent the T. indecoms. 



An extremely embarrassing species is the one under consideration, 

 as Dr. Fischer truly remarks. Both Fischer and Watson have dis- 

 cussed at length its synonymy, each arriving at a different conclu- 

 sion. I have been over this barren ground again a task full of toil 

 and difficulty, and have been forced to adopt still another name for 

 the shell. I am convinced that the T. sauciatus of Koch is identical 

 with this species instead of with T. sagittiferns Lamarck. I will 

 briefly rehearse the history of the above names : T. citrinus Gnael., 

 1788, is unidentifiable; T. listeri Wood, 1828, is probably this 

 species, but the figure is poor and no description is given ; T. sauci- 

 atus Koch (pi. 24, figs. 95, 96) corresponds perfectly with depressed 

 specimens of this species ; T. colubrinus Gould, is doubtless the same, 

 but later in date. I cannot follow Fischer in uniting T. indecorus 

 and T. sauciatus with T. sagittiferus Lam. The differences between 

 these forms are indicated under the next species. 



M. sauciata is like the Mediterranean M. articulate, M. turbinata, 

 etc., in the convex columellar lobe ; but agrees with the section 

 Oxystele in having a thin acute edge to the columella, and a thin 

 shell. The coloration is excessively mutable, as well as the general 

 form. 



M. SAGITTIFERA Lamarck. PL 23, figs. 65-67 ; 76. 



Shell conical, imperforate, rather thin ; ground-color (usually) 

 whitish, pinkish or bluish, painted with red, brown or blackish in 

 innumerable patterns, but usually in one of the following modes : 

 (1 ) longitudinal zigzag dark stripes 011 a light clear ground ; (2) very 

 obliquely descending narrow stripes or lines, generally zigzag or 

 interrupted about the middle of the whorl; (3) narrow spiral 

 articulated bands around the middle of the whorl, the base mottled 

 or barred, and the suture bordered by a row of dark blotches; (4) 

 ground-color pink or purplish, the entire surface variegated by rather 



