8 Dr. J. C. Melvill on Marine Mollusca 



basin omnino evanidis, uudique spiraliter striatulis ; apertura 

 rotunda, pcristomate tenui, contiuuo, columella paullum excavata. 

 Long. "I'lb, lat. 1-75 mm. 



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

 5G° .54' E., 156 lathonis, sliell-sand. 



An inflated, gradately-whorled Rissoa of great tenuity, 

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

 altogetlier in sculpture, and also from R. veisoverana, both 

 these being inhabitants of the same seas. Tiiis 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. (owusendi. 



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



i?. testa cylindrica, semipellucida, delicata, tenui ; anfractibus 5-G, 

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

 caeteris 3| ad euturas impressis, veutricosis, h^vibus, ultimo pro- 

 longate, paullum obliquo ; apertura ovata, peristomate contiuuo, 

 columella obliqua. 



Long. 3, lat. 1 mm. 



Ilah. 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 i?. {Scrohs) columen^, Melv., from the Gulf 

 of Oman at 150 tathoms, 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.) 



B. testa attenuata, oblonga, parum nitida, pallida 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 prolongate ; apertura ovata, labro tenui, continue, colu- 

 mella fere recta. 



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



Bab. Karachi, 1906. 



A single specimen, but in my opinion possessing cliaracters 

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



• Proc. Mai. Soc. Lond. ri. p. 53, pi. v. fig. 21 (1904). 



