﻿202 COPEPODA 



which it agrees in a few features, on account of its size and the spinous lamina along the outer margin 

 of the second basipodite of the third foot. 



Scaphocalamis globiccps, obfiisi/roiis. validus and rohnstiis seem to be nearh' related, and are, without 

 detailed investigation rather difficult to distinguish from each other. In contrast to Scott, who refers 

 them to Scolecithricclla, I follow vSars, and regard them as more nearly XQ{'a.\.&^ to Scaphocalanus )iiag- 

 ?ins, with which they agree l)y the number of segments in the antennulae, by the appendages of the 

 maxillae, and b\- the structure of the fifth foot in the male. About the differences between S. robusfus 

 and globicefs I refer to the former species. The female ol S. globiccps is characterised by slender shape 

 comparativeh' short antennulae, which have a single setae in segment lo and a Spr. in segment 17. 

 Se Re I pes I is long and slender, and Se Ri I pes II is short and clumsy. St. Re III pes II has 

 about 20 well .separated teeth. The inner terminal seta of the anterior surface of Ba.sp. Ill pes III — IV 

 is onlv poorly developed. The second basipodite of the third pair of legs has, laterally, a spinous lamina. 



64. Scaphocalanus robustus Th. vScott. 

 (PI. VII figs 12 a— c; text-figs 64 a— c). 



1.S94. Aiuallophora robusta 11. sp. Tli. Scott, pp 56 — 57, pi IV 1S96. Scolecillirix robusla J'li. Scott. Giesbrecht&Schineil, p. -17. 



figs 24—26. 1908. — — — Karraii, p. 57, pi. VI fig ,v 



Description, f?. Size of specimen from Thor St. 167 was 278 mm.; anterior division 2'i2 mm.; 

 urosome o'66 mm. Scott's specimen measured 3 mm. and I'^arran's 2'65 — 31 mm. 



The rostrum has rather short filaments (text-fig. 64 a). Tiie head is distinctly raised, and the 

 body is rather robust; the first thoracic somite is fused with the head, and the fourth and fifth thoracic 

 somites with each other; the lateral corners are slightly produced and rounded. The genital somite 

 is onl\- slightly produced below; the receptaculuni seminis is elongated and slender, but rather short 

 (text-fig. 64 b). The comparative length of the abdominal somites and the furcal branches is 33, 20, 18 

 10 and 14; the genital somite is almost as wide and deep as long, and the furcal rami are a little longer 

 than wide. The serration along the hinder margin of somites 2 — 4 is well developed. 



The aiitiiDuilnr extend to the end of the genital somite; the limitation between .segments 24 

 and 25 is rather indistinct; the appendages are like those of S. globtceps, with a single seta in segment 

 10, and 2 in segment 17. The measurements are similar to tho.se of the preceding species; the segments 

 19 and 16 are almost of equal length, and 1-3 as long as .segments Sc^g, which are, again, a little shorter 

 than segment 15. The antennae, mandibtilne, iiiaxillulae and maxillipcds are like those found in .S'. 

 globtceps. The maxillae possess 4 amalliform and 4 vermiform sensory appendages. 



When the natatory legs sitting on the animal are examined from the side, a curious difference 

 is found between the 3 first pairs and the fourth pair of legs in the basipodites as in related species; 

 the posterior surface of the three first pairs is seen to be excavated, while that of the fourth pair 

 appears cylindric, and in lateral view is almost twice as deep as that of the third foot. The first foot 

 is very much like that of .V. globiceps. but the Se Re I scarcel>- extends to the end of Re II (text-fig. 

 64 c). The second foot has the outer-edge spine of the first outer segment long and sickle-shaped, and 

 the outer-edge spine of the first inner segment short and rounded; the St has 30 short, well separated 



