from near Mount Wellington. 23 



which is fairly distinct. The virgnla is free for about 6 mm. 

 The three spines from which the species takes its name are well 

 marked ; in fact, they and the virpfula are all that remain of 

 many specimens. Carruthers pointed out the great variation in 

 length in the Scotch examples, and the same curious mixture of 

 different growth stages is found with us. None of the specimens 

 before me show much detail. They are almost too nebulous to 

 draw, and Lapworth says that it was only after the accumula- 

 tion of much material that he was able to determine the charac- 

 ters which induced him to found the subgenus.^ 



Lasiograptus, sp. 



A small fragment 2.5 mm. long apparently belongs to this 

 genus. Four or five thecae are present on each side. The 

 lateral appendages are long and slender, and are connected by 

 a single -thread along their distal ends. It occurs on the same 

 slab as about 30 examples of Cryptograptus tricomis and a 

 couple of Climacograptus wellingtonensis. 



Dicellograptus elegans, Carruthers. (PI. VI., Fig. 5). 



Branches about 6 mm. long ; at first almost parallel, then 

 bending outwards and finally inwards, the shape of the poly- 

 pary resembling a pair of engineer's callipers. Sicula short 

 and broad, there being no evidence of a virgula or ■sdrgella in 

 the only two examples before me. Lateral spines short, but 

 distinct. Thecae apparently about 15 in. 1 cm., but not well 

 enough preserved for accurate counting ; their outer walls 

 curved ; the apertures turned laterally in deep excavations. 



Miss EUes and Miss Wood^ say that the virgella is always 

 well developed. Its apparent absence in the specimen figured 

 may well be due to imperfect preservation. The thecae in the 

 British specimens are said to number from 8 to 10 in. 1 cm. 

 My estimate of 15 is very doubtful, as only two or three can 

 be seen. The extreme broadening of the distal ends of the bran- 

 ches shown in my figure is due to the blurring produced by 

 weathering in the orisfinals. 



1 See Lapworth, Ann. Ma;;. Nat. H. ser. 5, vol. v., 1880, p. 171. Tlie name of the sub- 

 genus is misprinted " Cyrtograptus." 



2 Loc. cit., p. 159. 



