281 ZOOPHTTOLOGY. 



that it may, by that character alone, be at once distinguished. 

 In the younger patches the surface is shining and glossy, 

 and, in this condition, the three marginal spines are usually 

 present ; and the outline of the orifice is distinct and free. 

 Very soon, however, the walls appear to thicken, and to 

 become irregularly bossed, especially around the orifice, 

 which is thus lodged in a sort of irregular depression. 



5. L. vulgaris, Moll. 



6. L~ marsupiala, n. sp. PI. XXXT, fig. 4. 



Cellulis ova/is, superficie granulosa, obscure punctata ; orijicio semi' 

 circulari, labio inferiori recto, integro, superiori spinis sex validis, articulatis 

 quorum infimis furcatis armato ; 'poro lunato medio infra orificium rostro 

 poculiformi obtecto ; ad unum talus cellules vibraculo, seta nigra. 



Cells ovate ; surface granular, with scattered fine pnncta ; orifice semi- 

 circular or arched above, lower lip straight, entire ; six large articulated 

 spines on the sides and above, the lowermost of which on either side is 

 forked at the extremities; a lunate pore in the middle, a short distance 

 below the orifice, protected below and on the sides by a pouch-like rostrum ; 

 a long, slender vibraculum,witha black seta on one side of the cell, towards 

 the upper part. 



Hub. — Madeira, on shell, /. J'. J. 



A very well-marked and beautiful species. The marginal 

 spines are distinctly articulated, as in L. Gattyce, Bk., and 

 one or two others, by a horny substance of a black colour. 

 They are consequently readily broken off. 



7. L. Woodiana, Bk. 



This agrees in all essential characters with L. Woodiana of 

 the Crag, and which has been found in the living state in 

 Ireland by Mr. Hincks. The Madeiran specimens, however, 

 differ in some respects, and chiefly in the greater development 

 of the cup-like peristome, and the apparently larger size of 

 the avicularia on the shoulders of the cell. Another difference 

 also may be found in the apparent absence of the scries of 

 marginal punctures observable in L. Woodiana. If it should 

 prove a distinct species, it will probably be found to coincide 

 with L. Dutertrei, Audouin (sp.) 



8. L. see I el os, Bk. 



/3. No oral spines. 

 L. unicornis, Johnst. 

 1 L. alba, Hincks. 



11. L. concinna, Hk. 



2. Inarmatse. 



a. Withoui oral spines. 



12. L. Mangnevilla, \ud. PI. XXXI, fig. 5. 



