314 Dr. P. P. Carpenter on new Forms of MoUusks. 



Genus Bryophila*. 

 Animal Aviculidaeum, viviparum : inter algas, etc., habitans. 

 Testa Pinnaeformis, extus prismatica, intus subnacrea : ligamentum 

 solidum : umbones extantes, terminales, intus concavi. 



10. Bryophila setosa. 



B. testa parva, regular! ; cinerea, salmoneo seu chocolateo, intus sub- 

 nacreo, exquisite tincta : t. juniore planata, semirotundata, dor- 

 saliter recta, sequilaterali, conspicue punctata : t, adolescente sub- 

 diaphana : t. adulta solidiore ; umbonibus rectis, terminalibus, 

 intus alte excavatis ; marg. dorsali breviore, recto ; antico recto ; 

 ventrali et postico late rotundatis : extus epidermide subspongiosa 

 vestita, radiis setarum subdistantibus, marginibus eleganter pecti- 

 natis : intus ligamento solido dorsaliter producto ; limbo pallii 

 eequaliter prope marginem decurrente ; cicatr. adduct. submediana, 

 inconspicua ; postice hiante ; antice propter byssum tenuem si- 

 nuata. Long. '13, lat. '2, alt. '1 poll. 



Like a minute Pinna, or a transverse Margaritiphora without 

 ears, or an Isognomon without pits. Differs from the other 

 Aviculids in being viviparous, like some other minute bivalves. 



11. tAtys casta. 



1A. testa elongata, tenui, subdiaphana, albida ; antrorsum paulum 

 tumidiore ; spira celata, lacunata, (t. adultse) baud umbilicata ; 

 columella paulum intorta, effusa ; umbilico antico minimo ; labro 

 postice producto, obtuse angulato ; tota superficie subtiliter spira- 

 liter stnatula. Long. 'A, lat. '18 poll. 



On the confines of the genus, related to Cylichna. 



12. Ischnochiton parallelus. 

 7. testa ovata, subelevata (ad angulum 120°) ; rufo-fusca, olivaceo 

 tincta ; valvis latis, marginibus parum rotundatis, interstitiis par- 

 vis ; valvis intermediis valde insculptis ; areis lateralibus seriebus 

 granulorum a jugo radian tibus circiter vi. ; interdum irregularibus, 

 granis rotundatis, separatis, extantibus ; areis centralibus clathris 

 creberrimis, jugo parallelis, horridis, extantibus, interdum granu- 

 losis, ornatis ; valvis terminalibus seriebus granulorum, circ. xx., 

 interdum bifurcantibus, ut in areis lateralibus, ornatis ; mucrone 

 vix conspicuo ; limbo pallii angusto, pilulis furvicaceis creberrimis 

 minutis conferto ; lobis valvarum bifidis, terminalibus fissuris 

 circ. xi. a parte externa simplici disjunctis. Long, '7, lat. '48, 

 alt. -16 poll. 



Belongs to the group with minute setose scales. 

 13. Ischnochiton (? var.) prasinatus. 

 I. testa I. parallelo forma et indole simili, sed vivide viridi ; ar. 

 diag. seriebus bullularum irregulariter ornatis ; ar. centr. clathris 

 * Bpvov, sea-moss ; (/>tXoy, loving. 



