1910.] ANATOMY OP THE FRILLED SHARK. 541 



There are several reasons why a detailed knowledge of this fish 

 is especially desirable. In the first place, Chlamydoselachus 

 anguinevs is admittedly a primitive member of the Selachian 

 group of fishes, and by virtue of its position, it demands a more 

 considerable knowledge of its structure and anatomy than would 

 be the case were it a member of one of the higher and more 

 specialized groups of Selachians. Furthermore, the original 

 account of the fish given by Garman (10) is in many parts very 

 limited and indefinite, whilst the figures are rather indistinct and 

 in a few cases inaccurate. Little work has been carried out on 

 the anatomy of the skeleton since the publication of this paper. 

 (Jiinther (14) has dealt with the skeleton of the mixipterygia and 

 with the abdominal viscera. Braus (2 & 3) has dealt with the 

 pelvic plexus in the earlier of the two papers, and in the second 

 one has given a short comparative account of the pectoral girdle 

 and fin and of the mixipterygia. Fiirbringer (6) has described the 

 labial cartilages and the vestigial seventh branchial arch, which 

 were not discovered by Garman. 



In addition to these, there is a paper by Ayres (1) on the com- 

 parative anatomy of the arterial system, and two papers by 

 Hawkes (16 & 17), the first on the cranial and spinal nerves, 

 and the second on the abdominal viscera and the vestigial seventh 

 branchial arch. 



My best thanks are also due to Prof. Gamble for many helpful 

 suggestions during the progress of the work since the death of 

 Prof. Bridge. 



II. Measurements. 



I give certain measurements which may be of service as indi- 

 cating the size of the specimens examined and also as perhaps 

 denoting in an indirect way their comparative age. 



Total length, 52 ins. (Garman's specimen 59 - 5 ins. Giinther's 

 58 ins.). 



Snout to angle of mouth 3'5 ins. 



,, to end of gill-covers 7'7 ,, 



,, to end of left pectoral fin 11 



,, to base of pelvic girdle 25"5 ,, 



,, to anus 27 „ 



,, to base of anal fin 31 "8 ,, 



„ to end of anal fin 38"8 „ 



„ to base of dorsal fin 32 - 5 ,, 



„ to end of dorsal fin 38 ,, 



Greatest depth of caudal fin 3*7 ,, 



Width across anal and dorsal fins 4 - 8 ,, 



Width across eyes 2*8 „ 



Tail of large female specimen referred to in paper. 



Length of tail from root of caudal fin to tip ... 18 ins. 

 Greatest depth of caudal fin 5 „ 



