104 LIMNiEID^. 



of L. peregra. Very little is known with respect to the 

 external parts of the body; but Professor Goodsir has 

 given some valuable details of its internal organization, 

 which are published in an appendix to Mr. Thompson's 

 paper in the ^Annals of Natural History/ He says, 

 '' In structure the Limnaus involutus resembles the other 

 species of the genus ;^' from wliich remark it might be 

 inferred that the mantle has not the expanded lobe 

 which is peculiar to the subgenus Amphipeplea. Dr. 

 Perceval Wright, however, informs me that the greater 

 part of the shell in this species is covered by the mantle, 

 as in L. glutinosa. The form and substance of the shell 

 are also similar in both of these species. 



B. Exterior of the shell never covered by the mantle : spire 



produced. 



3. L. PER EGRA*, Miiller. 



Buccinum 'peregrum, Miill. Verm. Hist. pt. ii. p. 130. Limnmcs fcreger, 

 F. & H. iv. p. 168, pi. cxxiii. f. 3-7. 



Body yellowish-grey, with a brown or olive-green tinge, 

 mottled with black and covered with small yellow or milk- 

 white, and black .specks : tentacles diverging from each other 

 at nearly a right angle : eyes distinct : foot oblong, very broad, 

 nearly truncate in front, and obtusely rounded behind. 



Shell obliquely ovate, thin, moderately glossy, semitrans- 

 parent, yellowish-horncolour, irregularly striate by the lines 

 of growth, and closely and microscopically striate in a spiral 

 direction, with occasionally a few indistinct spiral ridges and 

 pitmarks : epidermis rather thin : ivhorls 5, convex, the last 

 occupying three-fourths of the shell : spire produced and 

 pointed : suture rather deep : mouth large, oval, very Httle 

 contracted above by the projection of the penultimate whorl : 

 outer lip thin, slightly reflected : inner lip folded on the colu- 

 mella and thickened, forming behind it a slight umbihcal cleft : 

 fold rather prominent and curved. L. 0-75. B. 0*425. 



* Traveller. 



