//. Woochvard — Nc7v Fossil Crustacea. §61 



(having a general resemblance to the recent Palinurus) found in the 

 Lithographic stone of Solcnhofen. 



In a paper by Mr. Charles Moore, F.G.S., published in the 

 Proceedings of the Somersetshire Archaeological and Natural 

 History Society, vol. xiii. (Taunton, November, 1867), I have 

 recorded the occurrence, among many others, of two species of 

 Palinicrina in the Upper Lias of Ilminster, identical with those 

 occurring in the Solcnhofen slates described l)y Miinster — namely, 

 Paliniirina pygmcea and P. lomgifes} I have now to rec(3rd the occur- 

 rence of this last-named species in the Lower Lias of Lyme Regis, 

 discovered by Mr. E. C. H. Day, F.G.S., late of Charmouth, and 

 now of Columbia College, New York, U.S. 



Description. — This elegant little Crustacean measures 2 inches in length, whilst 

 the large and rigid anteunsc are of equal extent with the entire body. The anten- 

 nules, not clearly seen in the specimen (fig. ob.) are 8 lines in length, and are divided 

 above the third joint into two multi-articulate sctic of equal length ; the outer pair of 

 antennae have three large and scabrous basal joints, 1 line in breadth, and 1;^ in length, 

 succeeded by stout multiarticulate setoe 20 lines in length, apparently but little 

 flexible, as they are always found lying nearly in a straight line. 



The late Dr. Oppel has pointed out that the articuli of the antennas in the Solcn- 

 hofen specimens are fringed with very minute hairs : ^ these cannot, of course, be de- 

 tected in our Lias example. The five pairs of thoracic limbs are all monodactylous, 

 the first pair being the stoutest and somewhat shorter than the succeeding : they are 

 all scabrous like the bases of the antenna). The surface of the carapace and abdominal 

 segments is finely granulated, the former having a row of rather larger granules ar- 

 ranged in pairs down its centre. The abdominal segments decrease slightly towards 

 the telson, the first being 4 lines and the fifth 3 lines in breadth, by rather more than 

 a line in length. The tail-plates, whicli Avere broad and well adapted for swimming, 

 are but imperfectly preserved in any of the specimens I have examined. 



Within the past few years an extremely large number of Crustacea 

 have been met with in our Lias, common also to the Solcnhofen 

 stone : as many as seven genera and eight species being apparently 

 found in both. 



The })ersistence of such forms as Eryon, Eryma, Glyplioea, and 

 Paltannna through the whole Oolitic series, seems clearly to de- 

 monstrate that having escaped total extinction in the Lower Lias 

 sea, they migrated from time to time to more favourable areas, and 

 thus were enabled to live on during the periods of time represented 

 by the long series of deposits, from the Lower Lias to the Litho- 

 graphic stone, in which so many are found fossil.^ 

 EXPLANATION OF PLATE XIV. 

 Fig. L Fyrgoma crctucea, PI. Woodw., Upper Chalk, Norwich (exterior view) 

 natural size. 



,, 2. Fyrgoma cretacea, interior view of the same; natural size. 



„ 2«. „ „ portion of the shell, much enlarged, to show costae. 



,, 3. Fyrgoma anglicum, Sby. (greatly magnified view), Cor. Crag, Sufi"olk. 



„ 4. Necrocarcinus tricarinahis, Bell, sp. Gault, Folkestone ; nat. size. 



,, 5. Falinurina longipes, Miinst., Lower Lias, Lyme Ecgis; nat. size. 



„ ba. Portion of one of the antenna magnified f (after Oppel). 



,, 5b. One of antennules magnified ^ (after Oppel). 



The above specimens are all preserved in the British Museum. 



' See also British Association Report for 1867, Third Eepor on the Structure and 

 Classification of the Fossil Crustacea. 



- See Oppel's Palseontologische Mittheilungen, etc., Stuttgardt, 1852, p. 86, 

 Taf. 24, fig. lb. ; see also our Plate XIV., fig. 5a. 



3 See Brit. Assoc. Report on Foss. Crustacea, 1867. p. 46. 



