GENUS TINTINNUS. 607 



inflated and ornamented with four longitudinal grooves or sulci, the anterior 

 margin widely everted. Animalcule elongate-ovate, occupying, when 

 retracted, the entire posterior half of the lorica. Length of lorica I-125". 

 Hab. — Salt water : Norwegian coast (C. & L.). 



Tintinnus quadrilineatus, C. & L. Pl. XXXI. Fig. 13. 



Lorica transparent, homogeneous, shortly vase-shaped, about three times 

 as long as broad ; anterior margin widest and largely everted, gradually 

 tapering towards the posterior extremity where it terminates in an obtuse 

 point ; four deep grooves extending from the posterior extremity nearly as 

 far as the anterior margin. Animalcule undescribed. Length of lorica 

 1-150". Hab. — Norwegian coast (C. & L.). 



Tintinnus denticulatus, Ehr. Pl. XXXI. Figs. 18 and 19. 



Lorica diaphanous, cylindrical, two or three times as long as broad, 

 terminating posteriorly in a long acute point, surface regularly shagreened 

 with minute hexagonal facets ; the anterior margin finely denticulate, not 

 everted. Animalcule unobserved. Length of lorica 1-175". 



Hab. — Salt water : Baltic Sea and Norwegian coast. 



ClaparMe and Lachmann, who met with this species abundantly on the coast of 

 Norway, remark that the lorica is of very variable form, the width being sometimes 

 equal to the length, while occasionally the posterior portion, before narrowing off to 

 the terminal subulate point, is considerably inflated. The very beautiful hexagonal 

 facetted structure of the test, as reproduced at Pl. XXXI. Fig. 19, is only exhibited 

 under a high magnification, the facets under a moderate magnifying power present- 

 ing the appearance of minute circular areas. Unfortunately no account of the 

 animalcule inhabiting this elegant lorica has been placed on record by Ehrenberg, 

 or Claparfede and Lachmann, which thus leaves it doubtful whether we have here 

 the protective sheath of a true Tinfinnus, or the facetted test of a Dictyocysta or 

 Codondla. Tintirmus denticulatus, while described by Ehrenberg in the year 1840,* 

 was first met with abundantly by Professor C. Boeck, in the vicinity of Spitzbergen, 

 in the year 1839, and subsequently by the same investigator in the Fjord of Christi- 

 ania. Its distribution would appear to be general and abundant throughout the seas 

 of Northern Europe. 



Tintinnus Ehrenbergii, C. & L. Pl. XXXI. Fios. i and 2. 



Lorica colourless, evenly cylindrical, very thick, finely granulate, about 

 three times as long as broad ; posterior extremity rounded, and then pro- 

 duced into a short, obtuse and usually curved, spur-like point ; anterior 

 margin even, not everted. Animalcule pyriform, attached posteriorly by 

 a pedicle which equals its body in length, occupying, when retracted, about 

 one-third of the interior of the lorica ; contractile vesicles two in number, 

 posteriorly located. Length of lorica 1-120". 



Hab. — Salt water: Norwegian coast (C. & L.). 



Clapar^de and Lachmann describe this form as exceeding, in both the dimensions 

 of the animalcule and in the size and thickness of the lorica, any other species met 



* 'Monats. Bed. Akad.,' p. 201, 1S40. 



