184 OPEAS, POLYNESIA. 



Stenogyra gyrata MOUSSON MS. in Mus. Godeffroy, 1885 

 teste Garrett (undescribed). 



Opeas junceus Gld., SYKES, Proc. Malac. Soc. Lond. vi, p. 

 112, f. 1. (Hawaiian Is.). 



Bulimus pyrgiscus PFR. P. Z. S. 1861, p. 24; Malak. Bl. 

 1861, p. 15; Monogr. vi, p. 97; Novit. Conch, p. 425, pi. 96, 

 f. 10-12. Opeas p., SYKES, Proe. Malac. Soc. vi, p. 113, f. 4. 



"Differs from 0. subula chiefly by the distinct longitudinal 

 striae" (Pfr.). The short aperture, not much exceeding one- 

 fourth the shell's length, and the deep suture, below which 

 the whorl is abruptly swollen, are characteristic, and in full- 

 grown shells serve to separate the species from 0. gracile. 



In this species the whorls are not very convex but the su- 

 tures are very deeply impressed. The surface is finely striate 

 and usually not very glossy. Under a compound microscope 

 some fine spiral strife may usually be seen. The umbilical 

 crevice is very narrow. There is often a small prominence 

 near the base of the columella, but in many lots this is want- 

 ing. The apical whorls are smooth. There is a good deal 

 of variation in size. 



Mr. Sykes gives no reference to connect his 0. oparica with 

 Pfeiffer's B. oparanus, yet the similarity of the names sug- 

 gests that oparica, is an emendation or error. The references 

 given above probably pertain in part to 0. gracile. Steno- 

 gyra (Opeas) striolata Pease, Sandwich Is., (W. Newcomb), 

 recorded in Nevill, Handlist Ind. Mus., Moll., pi. 1, p. 166, 

 1878, Stenogyra bacillaris Mouss., Paetel, Catalog, p. 104, 

 Tutuila, and Obeliscus annaensis Beck, from I. Annaa, Index 

 Moll. p. 62, are nude names, applying perhaps to forms of 

 0. oparanum or gracile. 



Andrew Garrett considered all Polynesian Opeas to be- 

 long to one species, which he called 0. tuckeri Pfr. I have 

 elsewhere shown that the real tuckeri does not enter Poly- 

 nesia. The Polynesian specimens I have seen are divisible 

 into two species: (1) 0. gracile with regularly rounded 

 whorls usually puckered below the suture, and. a long, rather 

 narrow aperture, and (2) a form with the later whorls more 

 flattened, tumid below the deep suture, the aperture de- 



