8 Dr. J. C. Melvill on Marine Mollusca 



basin omnino evanidis, undique spiraliter striatulis ; apertura 

 rotunda, peristomate tenui, continuo, columella paullum excavata. 

 Long. 2-75, lat. 1-75 mm. 



Hab. Karachi, 1906 ; Gulf of Oman, lat. 24° 58' N., long. 

 56° 54' E., 156 fathoms, shell-sand. 



An inflated, gradatelj-whorled Rissoa of great tenuity, 

 being evidently an abyssal species. It differs from R. charope 

 altogether in sculpture, and also from R. versoverana, both 

 these being inhabitants of the same seas. This last is a 

 much more solidly constructed shell, more compact, of brown 

 colour, or white flecked with brown, two forms occurring, 

 one of which, owing to its obese body-whorl, the more 

 approximates R. townsendi. 



Rissoa {Scrobs) elspelhce, sp. n. (PI. I. fig. 12.) 



H. testa cylindrica, semipellucida, delicata, tenui ; anfractibus 5-6, 

 quorum apicales tumidi, ad apicem ipsum deplanati, dein bulbosi, 

 caeteris 3| ad suturas impressis, ventricosis, lsevibus, ultimo pro- 

 longato, paullum obliquo ; apertura ovata, peristomate continuo, 

 columella obliqua. 



Long. 3, lat. 1 mm. 



Hab. Mekran Coast ; Charbar, 40 fathoms. 



A very beautiful and delicate, though minute species, and 

 in local abundance at the above dredging, though we have 

 not yet discerned it from elsewhere. It is of the same form 

 but smaller than R. (Scrobs) columen*, Melv., from the Gulf 

 of Oman at 150 fathoms, and it is likewise quite smooth, the 

 larger species being uniformly spirally striate. I have 

 pleasure in connecting with this the Christian name of my 

 niece Mrs. Reginald Fletcher, who has always evinced great 

 interest in biological studies. 



Rissoa (Scrobs) ictriella, sp. n. (PI. I. fig. 13.) 



JR. testa attenuata, oblonga, parum nitida, pallide lirescente, tenui ; 

 anfractibus 6, quorum apicales duo, quorum apex ipse planatus, 

 simplex, caeteris ventricosis, apud suturas impressis, undique sub 

 lente delicatissime et obscure spiraliter striolatis, ultimo anfractu 

 paullum prolongato ; apertura ovata, labro tenui, continuo, colu- 

 mella fere recta. 



Long. 4 - 75, lat. 1-50 mm. 



Hab. Karachi, 1906. 



A single specimen, but in my opinion possessing characters 

 that merit differentiation. The shell is of a livid colour, 



* Froc. Mai. Soc. Lond. vi. p. 53, pi. v. fig. 21 (1904). 



