V( i889."'] PROCEEDINGS OF THE NATIONAL MUSEUM. 337 



convinces me that Githna Adams, is not a member of the family Lacu- 

 nidce nor allied to Fossarus, neither is the Japanese genus the same as 

 the Hela of Jeffreys. Indeed, Githna Adams, with its small pointed 

 apex and continuous peritreme does not offer any very good characters 

 which might separate it from Cingula or Littorinella. Owing to the fact 

 that several of Dr. Jeffreys' species of Hela or Githna are probably Vitri- 

 nellce, 1 did not at first recognize that the shells which I called Bentho- 

 nella were of the same genus as those first named Hela, by Jeffreys. 

 After the Blake Report was in type it suddenly occurred to me that it 

 was remarkable that Hela did not appear in the dredgings of the Fish 

 Commission, or the Blake. A re-examination of Dr. Jeffreys' material 

 revealed the fact that his original type, and also the Githna rnargari- 

 tifera of Watson should be referred to Benthonella. This genus J regard 

 as a thin-shelled deepwater member of the Rissoidw, with a blunt apex, 

 turbinate brownish nuclear shell and a thin paucispiral operculum. 

 The umbilicus is always small, bounded by a more or less evident ridge 

 or angle at the base, the shell is always thin and polished, the aperture 

 simple and sharp-edged, the peritreme interrupted by the body whorl, 

 and the pillar lip arcuated or passing insensibly into the rounded base. 

 The operculum is like that of Lithoglyphu's, as figured by H. & A. Adams, 

 thin, translucent horn color, without any process internally. The epi- 

 dermis, if any exists, is so thin and close as to seem absent. The spe- 

 cies which may be referred to Benthonella are, B. tenella (Jeffreys), B. 

 rnargaritifera (Watson), B. gaza, B. Fischeri, and />'. nisonis Dail. A 

 shell named tenella, by Jeffreys, from the Zanclean formation of Cala- 

 bria, is not Hela tenella Jeffreys, but is possibly a Benthonella. The 

 only specimen in the Jeffreys collection is somewhat abnormal. A 

 specimen marked Hela injlata Monterosato, seems to be a Vitrinella; 

 it was dredged by Nares, in the Mediterranean, in 200 fathoms. H. 

 fulva Jeffreys, from Korea (St. John), is not a Benthonella. Cithna 

 Adamsi, cincta, earinata, and naticiformis of Jeffreys (P. Z. S., 1883, pp. 

 111-112, pi. xx) do not belong to Benthonella nor to the original Cithna 

 of Adams. They resemble Vitrinella as much as anything else. 



A careful scrutiny of the specimens in the Jeffreys collection shows 

 that B. tenella was collected by the Porcupine in ISO!) at stations 1, 23, 

 23a, 30, 39, 40, and 41; in 1870 at stations 10, 17, 51, 54, and no. It 

 was also dredged in the Mediterranean by Spratt and Nares in 90 to 

 000 fathoms. B. rnargaritifera (which is very like B. Fischeri, but 

 ribbed transversely) was obtained by the Porcupine in 1870 at stations 

 16, 17, 17a, and 22: also in Setubal Bay and off Cape Espichel. 



Tne three West Atlantic forms seem uniformly larger than those from 

 the Mediterranean and Eastern Atlantic. All the species are closely 

 related and differ in details of form, size, and proportion rather than 

 by more salient characters. The dried animal remains in one of the 

 specimens of B. rnargaritifera together with the operculum, and I hope 

 later to examine the dentition of it. 

 Proc. N. M. 89 22 



