550 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.49. 



First pair of antennae small and inconspictioiis. Second pair of 

 antennae with first two segments short and subequal; third segment 

 hardly as long as first two combined; fom^th segment twice as long 

 as third ; fifth one- third longer than fourth ; fiagellum contains about 

 20 segments, and reaches to end of fourth thoracic segment. Maxilli- 

 ped has a palp of five articles (fig. 9). 



Segments of thorax subequal, with lateral margins smooth. 

 Epimera coalesced with segments, usually lighter in color than terga. 

 All six segments of abdomen distinct; the first two shorter than the 

 three following and with their lateral parts- covered by seventh 

 thoracic segment; third, fourth, and fifth segments successively 

 larger. Sixth or last abdominal segment with lateral margins par- 

 allel; posterior margin not produced but somewhat arcuate. Abdo- 

 men narrower than thorax. 



First pair of legs in male slender, with ventral border of merus 

 finely serrate. Copulatory appendage of male slender, linear, and 

 nearly straight. All legs ambulatory; with biunguiculate dactyh. 

 This species resembles L. haudiniana, but the first legs of the male 

 lack the armature characteristic of that species. 



It was abundant in the forest from above Minca to the top of San 

 Lorenzo. It fives in damp places, under leaves, logs, and stones, 

 and was often found in brooks. Females carrying young were taken 

 on July 15, 18, and 25. 



PROBOPYRUS BITHYNIS Richardson. 



A female of this species was found in the branchial chamber of a 

 MacrobracMum olfersii (Wiegmann) collected July 29 in a stream 

 near "La Rosa." 



DECAPODA. 



MACROBRACmUM OLFERSU (Wiegmann). 



This species was very common in the streams near "La Rosa" 

 (fig. 1), in the Manzanares River at Santa Marta, and in the Gaira 

 River. On July 29 and 31 and on August 1 large (54, 45.5, 46.3, 

 42.5, 47, 66.7 mm.) females carrynig eggs were taken in the rivers 

 and irrigating ditches near "La Rosa." The largest specimen cap- 

 tured, a male measuring 73 mm. in length, was found in a ditch at 

 the same place. About 300 specimens of all sizes were collected. 



This prawn usually rested under stones, among fallen leaves or 

 aquatic vegetation in the larger streams. It is widely distributed 

 through the West Indies, Mexico, Central America, Venezuela, Brazil, 

 and West Africa. 



MACROBRACmUM ACANTHTJRUS (Wiegmann), 



This was the only prawn collected at Fundacion, where it was 

 common in the small sluggish streams; it was not found at any of the 

 other localities visited. Eighteen specimens were collected. Females 



