10 gQ CRUSTACEA. 



anterior penult less than half shorter, anterior antepenult obsolete. 

 Shorter branch of second antenna two-jointed. Abdomen very 

 short. Caudal stylets extremely short. 



Plate 75, fig. 1 a, animal, enlarged ; b, under view of anterior part, 

 more enlarged {a, base of anterior antennae; b, posterior antennas; c, 

 mandible ; c', mandibular palpus ; d, maxilla and palpus ; e, maxil- 

 liped ; /, first pair of legs, in part ; m, buccal mass ; n, furcate appen- 

 dage to beak) . 



Collected in the Sooloo Sea, southwest of Mindanao, February 1, 

 1842. 



Length, one-fifth of an inch. This species is much narrower for 

 some distance posterior to the first pair of antennae than across the 

 middle, and the second pair of antennae is remote from the first pair. 

 The beak is very long and slender furcate. The abdomen is singu- 

 larly short and but two-jointed; the last joint very short also, and 

 bears the stylets at its truncate posterior angles, these stylets hardly 

 projecting beyond the posterior margin of the joint. 



The anterior antennae have a barely perceptible curve towards 

 base. The apical setae are spreading and a little bent, and all 

 are longer than apical joint ; the penult anterior is half the posterior, 

 and about as long as apical joint ; the anterior antepenult appears 

 to be obsolete ; the anterior of next joint preceding is as long as 

 the longest apical seta. The third joint of the antenna is in fact 

 a part of the second ; its seta is as long as first three joints, and 

 it is directed straight forward. The setae of the second pair of an- 

 tennae and following organs are rather short, the length scarcely 

 equalling the greatest breadth of the cephalothorax. The branches 

 of the second pair of antennae are unequal ; the shorter consists of two 

 subequal joints, and the other of two quite unequal joints, the second 

 being about half as long as the first. 



Calanus attenuatus. 



Elongaius. Frons triangidatus, acutus, rostro elongate et tenuiter furcato. 

 Cephalothorax antice valde angustatus, posticd obtusus, h-ariwulatus 



