46 PR J. H. ASH WORTH 



THE LARViE OF LINGULA. 



Previous Records of the Larvae of Lingula (s. lat.). 



(a) Lingula anatina Bruguiere. — Tlie larva of Lingula was first observed by 

 Semper (1861), who, in 1859, saw a free-swimming larva, without stalk, near 

 Zamboanga, Mindanao (Philippine Islands). Later (1864) he obtained several other 

 specimens, which fixed themselves in his aquaria and lived several weeks. Semper 

 gives no further information about his specimens, but no doubt they were larvae of 

 L. anatina, for this species was found in hundreds on the beach at Zamboanga by 

 the Challenger Expedition. 



Dr Yatsu (1902), while working at Misaki in Japau, obtained the fertilised eggs 

 of L. anatina, and has given a detailed account of the egg-cleavage aud of the larvae. 

 Captain Sewell (1912) published a short note on larvae, which he refers to this 

 species, from the coast of South Burma. 



(6) Glottidia audebarti (Broderip) = Lingula pyramidata Stimpson. — Early in 

 June 1860 M c Crady found in Charleston Harbour, South Carolina, a free-swimming 

 larva, and gave an account of it to the Elliott Society of Natural History on June 15, 

 which, however, was never published by the Society owing to the destruction during 

 the war of the notes and drawings of the larva. There is, in a letter written by 

 M c Crady (1860) to Stimpson on June 18, 1860, a brief description of the larva, and 

 M c Crady subsequently wrote from memory a further report upon it, which was 

 given to and published by Professor Morse (1873, p. 261). M c Crady, who believed his 

 specimen to be the young of "Lingula pyramidata," states that it had about 6 # 

 pairs of cirri, and that there was no trace of peduncle, but his description shows that 

 what he regarded as the intestine was undoubtedly the peduncle, which was evidently 

 of considerable length and convoluted. 



Brooks (1879), who was the first to study a series of larva? of " Lingula," 

 published an excellent account of the structure of the larva? of " L. pyramidata" 

 which he obtained in Chesapeake Bay (see pp. 56, 57). 



(c) Species unknown. — Professor Simroth (1897, p. 6), has recorded a larva with • 

 1 pairs of cirri among the material obtained by the Plankton Expedition from the 

 west coast of Africa. The larva was "66 mm. in transverse diameter, and had no 

 stalk. In its general structure and in the shape and dimensions of its shell this 

 larva approaches that of Lingula anatina, but the hinge-line is about one-fifth 

 shorter than in the larva? studied by Dr Yatsu and myself, and the protegulum is 

 also proportionately smaller. The shell of Professor Simroth's larva? is much larger 

 than that of the corresponding stage of Glottidia as described by Brooks, and is of 

 different shape ; the hinge-line is one and a half times as long, and the protegulum is 

 larger in a similar proportion. This larva, therefore, does not agree with either of 



* The number of cirri is probably considerably understated. 



