494 D)'. Henry Woodward — On a new Loricula. 



In the newly obtained specimens the upper exposed surface (Fig. 1) 

 of the capitulum shows the carina, see lettered Diagram-outline 

 figure (Fig. 2, c) ; the second or carinal latus {I) ; the first, middle, or 

 upper latus ^ (?') ; the tergum (^) ; the right scutum {set); and one 

 sees the inner occludent margin of the left scutum {set') exposed 

 beneath the right one. 



Fig. 2.— Diagram -outline of Loricula pulchella, Cr. B. Sowerby, var. minor. 

 (After Fritsch.) From the Chalk of Bohemia. 



Valves of Capitulum. — c, carina ; I, carino-latus ' ; t, tergum ; I', upper latus or middle 



latus - ; set, scutum ; set', edge of the pair-valve of scutum seen from the inside. 



(The small rostrum is not seen in any of the specimens, and was lost, or probably 



aborted.) 

 Peduncle. — sc, series of cai'inal scales ; cl, carino-lateral series of scales ; ml, raedio- 



lateral series ; si, series of scutal scales ; ss, sub-scutal (or sub-rostral) series 



of scales. 

 a, initial point of attachment of the young animal in the earliest stage of its becoming 



fixed and ceasing to be a free-swimming uauplius. 



In all the specimens at present known and examined, however, the 

 rostrum (usually a very small single valve lying at the base of the 

 paired scuta) appears to have been absent,^ but, arguing from the lines 

 of scales seen in the peduncle, Darwin believes that a rostrum most 

 probably existed. "With this exception the capitulum may be said to 

 be complete. 



The small size of the capitulum, and its narrowness compax'ed with 

 the breadth of the peduncle, led Darwin "to believe that the greater 



1 In his monograph on the Fossil Lepadidte (Pal. Soc, 1851) Darwin writes, p. 85 : 

 "In the imaginary restored figure [Tab. v, fig. 4, op. cit.] the tergum has its normal 

 shape and manner of growth. The first latus now answers to the upper latus in 

 Sealpellum, but it is interposed to a quite unprecedented extent between the scutum 

 and tergum [see Fig. 2, T] ; the second latus [see Fig. 2, /] is on this view the 

 carinal latus ; and the rostral latus, always smaller than the carinal latus, and in 

 Sealpellum qundratum and S. Peronii reduced to a very small size, is here quite 

 aborted." 



* r is spoken of by Darwin also as the first latus ; I is referred to by Darwin also 

 as the second latus. 



3 It seems not improbable that in Loricula the rostrum may have been aborted in 

 this curious parasitic form. 



