Bibliographical Notice. 257 



The close spiral striation of this species, being crossed by 

 the lines of growtli, lias a minutely subgranular appearance. 

 It is not apparent to tiie naked eye, but is distinctly visible 

 under a simple lens. 



30*. Planorhis Iticidus, Pfeiffer. 



Planorhishicidus, Pfeiffer, Wiegmann's Archiv f. Naturgesch. 1839, 

 vol. V. p. 534 ; Sowerby, Concli. Icon. fig. 53 ? (enlarged) ; Clessin, 

 Conch.-Oab. ed. 2, p. 193, pi. xxix. fig. 2. 



Hah. Cuba, Porto Rico, Guadeloupe, Martinique. 

 A single half-grown specimen is all that was obtained at 

 Barbados. 



31*. Paludestrina crystallina^ Pfeiffer. 



Paludina crystallina, Pfeiffer, Wiegmann's Archiv f. Naturgesch. 1840, 

 p. 253; Pbiljppi, Abbild. vol. i. p. 118, pi. i. fig. 18 (fig. 17, var. 

 coronata) ; Kiister, Conch.-Cab. p. 50, pi. x. figs. 7, 8 (figs. 9, 10, 11, 

 12, var. coronata). 



Hah. Cuba, Jamaica, &c. 



Both forms of this species, that with smooth whorls and 

 that with short spines, occur at Barbados. " It was met with 

 in Graime Hall Swamp, and was very diSicult to find. 

 They laid an immense number of eggs when captured." 

 {Feilden.) 



BIBLIOGRAPHICAL NOTICE. 



Handbooh of the London Geological Field-Class. Small 8vo, 215 

 pages, with 18 woodcuts. George Philip and Son. 1891. 

 London. 



This interesting little book consists of Lectures on the Geology of 

 the London district, by Professor II. G. Seeley, F.ll.S., and Reports 

 by Students of the excursions made, from the year 1886 to 

 1889, to examine practically the Physical Geology of the rocks 

 discussed in the Lectures. The plan of this Field-class Society 

 and its Director (Chairman) is " to teach the elements of Physical 

 Geography and Geology direct from Nature without preliminary 

 study from books ; " and, whilst taking their out-door recreation, 

 the Students are thus training their " powers of observation, imagi- 

 nation, and reasoning." Local scenery and all the features of the 

 surface are by these means not only directly noticed, but their 

 relations to the geological structure of the country are learnt, and 

 the causes and history of that structure are brought under notice. 



Ami. tf; ^fag. N. Hist. Ser. 6, Vol. viii. 17 



