VULSELLA. 



Plate I. 



Genus VULSELLA, Lamarck. 



Testa longUudhialis, fibro-laminark, aquivnlvis, stibirregu- 

 laria, umbonibus aqiialibus. Callitm cardinale in 

 utraque valvd prommulum, superne depressum, cum 

 fovea conicd oblique arcuatd desuper impressum, liga- 

 mento inserto. Lnpressio muscularis subcentralk, 

 versus basin dislincte imhtta. 

 Shell longitudinal, fibro-laroincar, cquivalve, somewhat ir- 

 regular, umboes equal. Hinge-callosity in each valve 

 prominent, depressed at the upper part, impressed 

 above with an oblic|uely-arched conical pit enclosing 

 the ligament. Muscular impression nearly ceutral, 

 distinctly marked towards the base. 

 The shells which constitute the genus Vulsella are all 

 of a dull-brown fibrous texture, of very irregular gi-owth, 

 living chiefly imbedded in sponge. They present great 

 similarity of sculpture, being mostly beset with laminae 

 of minute crenulated scales, and the umboes are inva- 

 riably attenuated and more or less hooked. The most 

 conspicuous structure of the hinge is a central spoon- 

 shaped pit, as in Mallens ; but besides this, the valves 

 incline to recede from one another at the base, so as to 

 form a sloping area. 



The list now numbers seventeen species, chiefly from 

 the Bed Sea. 



Species 1. (Mus. Cuming.) 

 Vulsella Pholadifoumis. Vul. iesld ehmgalo-trigond, 



gracili, decussatim Jimbriato-striald. 

 The Pholas-shaped Vulsella. Shell elongately tri- 

 angular, slender, decussately firabriately striated. 

 Hab. Ceylon ; E. L. Layard. 



Distinguished by its slenderly triangular Pholas-shape. 



Species 2. (Mus. Cuming.) 

 Vulsella Isocabdia. Fid. testa ovatd, depressd, umbo- 

 nibus intortis, concentrice squamato-laminatis, squamis 

 crenatis ; sordide alba obscure radiatd. 

 The Isocakdia Vulsella. Shell ovate, depressed, um- 

 boes turned inwards, concentrically squamately lami- 

 nated, scales crenated; dirty-white, obscurely rayed. 

 Eab. Red Sea. 



The surface of this species is almost wholly overlaid 



with a plating of finely-pointed scales, the umboes being 

 convoluted inwards, as in Isocardia. 



Species 3. (Mus. Cuming.) 



Vulsella Tasmanica. Vul. testa subtrigono-ovaid, rudi, 

 dislortd, umbonibtts parvis, dense squamato-striatis ; 

 ferrngineo-albd. 



The Tasmanian Vulsella. Shell somewhat triangu- 

 larly ovate, rude, distorted, umboes small, densely 

 squamately striated ; rusty-white. 



IIu2). Tasmania. 



Of very uncouth growth, closely scale-striated, and 



rusty-white. 



Species 4. (Mus. Cuming.) 



Vulsella Mytilina. Vul. testa oblongo-ovatd, aniice 

 subcompressd, solidiusculd, obscure decussatim squam.a- 

 to-striatd ; ferrugineo-albd. 



The Mytilus-shaped Vulsella. Shell oblong-ovate, 

 anteriorly somewhat compressed, rather solid, ob- 

 scurely decussately squamately striated ; rusty-white. 



Lamarck, Anim. sans vert. vol. vii. p. 268. 



Hab. Ked Sea ; Dr. Riippell. 



More sohd, and less definitely scaled than its congeners. 



Species 5. (Mus. Cuming.) 

 Vulsella attenuata. Vid. testa elongato-attenuatd, ad 

 extrendtatem depresso-subquadratd, radiatim obscure 

 squamato-striatd ; corneo-albidd, deinde livido-purpu- 

 rascenle-brunned. 

 The attenuated Vulsella. Shell elongately attenuated, 

 depressly subquadrate at the extremity, radiately 

 obscurely scale-striated; horny-white, then livid- 

 purple-brown. 

 Eab. Ecd Sea. 



The example of this species here figured may be more 

 than ordinarily attenuated, owing to some external condi- 

 tions in its situation of gn'owth. 



Species 6. (Mus. Cuming.) 

 Vulsella lingulata. Vul. testa elongatd, recta, concen- 



November, 1S58. 



