38 



„longiore,, utrinque rotundata; dente cardinali unico, den-" 

 „tibus lateralibus niacins." 



Fra Cragformen synes vor at afvige ved en mere 

 regelmæssig rund oval Form. 



Størrelsen er 2'""' anteriopost. 1.0""" umboventr. Diam. 



Forekomst: Den forekom kun paa St. 192 — 649 

 Favne. 



Dr. Jeffreys og Monterosata har nævnt den fra Korea, 

 Biscaybugten og Sicilien. 



Lyonciella Jeffreysi, Fr. 



Pl. XII, Fig. 15, 16. 



Lyonciella Jeffreys), Friele, „Cat. Spitzberg. Moll." Jahrb. 



Mal. Gesell. 1879, Pag. 269. 



Skallen noget solid, hvid, oval trapezoideformig; po- 

 sterior Dorsalrand næsten ret, anterior kort fremspringende 

 og i en nær ret Vinkel boier den ned mod Ventralranden, 

 der atter krummer stærkt op mod den svagt afrundede 

 posterior Rand. Unibonerne fremtrædende. foranbøiet og 

 incurvat; Partiet fra Unibonerne og ned til bågeste Ven- 

 tralrand er opsvulmet, Dorsalpartiet er derimod nedtrykt 

 og paa Skallens indvendige Side viser sig her en Fold. 

 Sculpturen bestaar af talrige, svagt hævede Linier, der 

 radierer ud fra Umbonerne mod Skallens Periferi, samt 

 tætte, men uregelmæssig stærke Vækstlinier. Laaslinien er 

 uden Tiender. Muskelindtrykkene tydelig. Indvendig er 

 Skallen perlemorglindsende. 



Størrelse: 23""" anteriopost. 26""" umboventr. Diam. 



Forekomst: St. 295, 312 fra 656 til 1100 Favne. 



I ,.Keport on the scientific Results of the voy of 

 Challenger" Zool. Vol. XIII Lamellibranchiata 1885, Pag. 

 73, Pl. XXV, Fig. 1, 1 6 har Mr. Edgar A. Smith ogsaa 

 beskrevet en Lyonciella Jeffreysi. Der synes ikke at være 

 saa liden Lighed imellem disse to. der tilfældigvis har faaet 

 samme Navn, men de er dog neppe nok samme Art. Mr. 

 Smiths Jeffreysi er nemlig foran mere truncat og ikke saa 

 fremspringende og posterior mere afrundet. For ikke at faa 

 Confusion vil jeg foreslaa Lyonciella Smidti for Challenger- 

 Arten. 



Det er mig en Tilfredsstillelse at se, at ogsaa Mr. Smith 

 (1. c. Pag. 165) under de kritiske Bemærkninger over Slæg- 

 ten Verticordia, Wood, kommer til de samme Resultater, 

 som jeg allerede i 1879 (,.Cat. Spitzb. Moll." Jahrb. Mal. 



„longiore, utrinque rotundata; dente cardinali unico, den-" 

 ,.tibus lateralibus magnis." 



Ours appears to differ from the Crag-form in having 

 a more regular rounded oval form. 



Size. Anterio-posterior diameter. 2""". umbo-ventral 

 diameter, 1 .(>""". 



Habitat: It occurred, only, at station No. 192. Depth 

 649 fathoms. 



Dr. Jeffreys and Monterosata have cited it from the 

 Corea, Bay of Biscay, and Sicily. 



Lyonciella Jeffreysi, Fr. 



PI. XII, tigs. 15, l(i. 



Lyonciella Jeffreysi. Friele ..Cat. Spitzberg. Moll.'- Jahrb. 



Mal. Gesell. 1879, pag. 269. 



Shell somewhat solid, white, oval-trapezoidal, posterio- 

 dorsal margin almost straight, anterio-dorsal margin short 

 and projectant, and curving at a nearly right angle, down 

 towards the ventral margin, which, again, bends sharply 

 upwards towards the slightly rounded posterior margin. 

 The umboes prominent, bent forward and incurvate. The 

 portion of the shell, from the umboes clown to the poster- 

 ior ventral margin is dilated. The dorsal portion is. on 

 the contrary, flattened, and upon the interior side of the 

 shell a fold is, here, visible. The sculpture consists of 

 numerous, slightly elevated, lines, which radiate from the 

 umboes towards the periphery of the shell, and. also, of 

 close lint irregular, strong, lines of growth. The hinge 

 line is devoid of teeth. The muscular impressions distinct. 

 The shell has. interiorly, a mother-of-pearl lustre. 



Size. Anterio-posterior diameter, 23""", umbo-ventral 

 diameter. 26""". 



Habitat: Stats. Nos. 295. 312. Depth, 656 to 1100 

 fathoms. 



In ..Report on the scientific Results of the Voy. of 

 Challenger" Zool. Vol. XIII. Lamellibranchiata. 1885, 

 pag. 73, PL XXV. figs. 1. 1 h. Mr. Edgar A. Smith 

 has, also, described a Lyonciella Jeffreysi. There appears 

 to be no inconsiderable resemblance between these two. 

 which have accidentally obtained the same designation, but 

 they pertain, however, barely enough to the same species. 

 Mr. Smith's Jeffreysi is. for instance, more truncate anter- 

 iorly and not so protuberant, anil its posterior is more 

 rounded. To prevent confusion, I would suggest Tjyonciella 

 Smidti as a designation for the Challenger species. 



It is with much satisfaction I observe that Mr. Smith, 

 also, (1. c. pag. 165) in his critical remarks upon the 

 genus Verticordia, Wood, arrives at the same results as I, 

 already in 1879. had expressed (,.Cat, Spitzb. Moll." Jahrb. 



