ATLANT. DEEP-SEA EXPED. 1910. VOL. Ill] 



C1RRIPEDIA. 



investigated 7 rows only could be made out. The capitulum 

 of Gruvel's specimen had the following dimensions: 

 Length 11 mm, Breadth 6 mm. The specimens collected 

 by the "Michael Sars" measured as follows: 

 The largest: Length 12 mm, Breadth 6-5 mm. 

 The second: — 10 „ 5-2 „ 



The smallest: — 8 „ 4-1 „ 



The differences are so small, and the general resem- 

 blance so striking, lhat these specimens must be regarded 

 as belonging to Gruvel's species. 



Gruvel's specimen was dredged near the Azores at 

 a depth of about 1000 m., and the "Michael Sars" 

 specimens a little to the south and east at a depth of 

 1215 m. 



Haarlem, October 16, 1911. 



After finishing the foregoing description of the Cir- 

 ripedia of the "Michael Sars" cruise, I received in April 

 1912 two tubes, each with a Nauplius-larva, which Mr. 

 Oscar Sund found among some Decapod larvae. A short 

 description of these Nauplii is given here. 



At Stat. 67, June 27, 1910, Lat. 40° 17' N., Long. 

 50° 39' W., two Nauplius-larvae were caught in two dif- 

 ferent hauls, which in most respects correspond with two 

 of the larvae fully described and beautifully figured by 

 Carl Chun in 1896. 



The one shows a great resemblance to the Nauplius 

 called by Chun Nauplius eques. I suppose the "Michael 

 Sars" specimen was taken with a plankton-net, the label 

 stating that 50 m of wire were out. Chun caught his 

 larva with an open net which was let down to a depth 

 of 1000 m between Madeira and Africa. Like Chun's 

 specimen, that of the "Michael Sars" has the shield-shaped 

 carapace thorny and the fronto-lateral horns standing 

 off horizontally. The posterior horns approach each 

 other somewhat, and the posterior margin of the carapace 

 is excavated,— not so deeply, however, as in Chun's figure. 

 The dorsal spine is longer than the tail, and only a little 

 shorter than the caudal spine. Both spines, and the tail 

 as well, are covered with thorns on their proximal half. 

 The dimensions also correspond with those of Chun's 

 specimen: length of carapace a little over 1 mm, breadth 

 0'8 mm, length of caudal spine between 8 and 9 mm. 



The other specimen looks much like Chun's Nauplius 

 loricatus, taken at a depth of 80 to 100 m, in the Gulf 

 of Naples, the "Michael Sars" specimen being taken at 

 Stat. 67 in Petersen's young-fish trawl with 200 m of 



wire out. The surface of the shield-shaped carapace of 

 the "Michael Sars" larva is thorny, furnished with a little 

 hump on its anterior half, and bears, at the place of the 

 dorsal spine, a short and strong thorn; the fronto-lateral 

 horns are directed obliquely forwards, the posterior mar- 

 ginal spines of the carapace (which are double in Chun's 

 Nauplius hastaius and single in his N. loricatus) are 

 single, and the caudal spine is moderately long. 



The dimensions of the "Michael Sars" specimen are 

 slightly different from those of Chun's N. loricatus:— 



Chun's "Michael Sars" 



specimen specimen 



Length of carapace... 1-5 mm 1-2 mm 



Length of caudal spine 5 „ 3 



Total length 6-5 „ 5 



These larvae are interesting because it is only the 

 second time that such big Nauplii have been taken in the 

 Atlantic Ocean. Chun, who collected them there for the 

 first time, was unable to determine to what species of 

 Lepadids they belonged, and I think I may say the same 

 for myself now. The Nauplius eques of Chun looks much 

 like Willemoes-Suhm's Nauplius of Lepas fascicularis, but 

 neither Chun nor I myself believe that they are identical. 

 Larvae of L. fascicularis have not as yet been observed 

 in the Atlantic; moreover the "Michael Sars" collected 

 these larvae in Long. 50° W., whereas the most westerly 

 station where Lepas fascicularis was met with during the 

 cruise was in Long. 16° W. L. anserifera was found at 

 the same station (67) as these larvae, and L. pectinata 

 at Stat. 69, not far off. It is of course possible that 

 these very curious larvae belong to these species. 



Haarlem, May 31, 1912. 



