TO INDIAN CAECINOLOGY, i49 



Considerable variation is seen iu the length of the tclson, and in some specimens the 

 marginal spinules are well developed, especially the subapical pair, while in others the 

 whole series is scarcely marked, or even altogether absent. 



Distribution. Indian Seas, Malay Archipelago. 



273. Pen^us Dobsoni, Miers. 



/'. dobsoni, Miers, Proc. Zool. Soe. p. ;502, pi. xvii. fiji. 2 (1878). 



Madras ; a female specimen, probably from Iresh water (J. It. H.). 



The surface of the body is slightly pubescent. The rostrum is styliform and slightly 



upturned distally, Avith the dental formula jj, the first tooth at some distance fro.n the 



second, and the fovu'th above the orbitil margin. The antennular liagella are about 

 equal in length to the peduncle. The first tliree pairs of legs are unispinose at the base. 

 The fifth pair of legs are rudimeutai'y in the female, being represented merely by a basal 

 protuberance on each side (while in males they arc normal, according to Miers). The 

 genital bursa or thelycuin * in the female is trefoil-shaped, with a central depression. 

 The total length of the Madras specimen is 103 mm. 

 Disiribiition. Mangalore, Western India (fliers). 



274. Pen^^us velutinus, Dana. 



P. vt'/utinus (Dana), Bate, 'Challenger' Macrura, p. 253, pi. \.\.\iii. fig. 1 (1888). 



Gulf of Martaban, a series {Oates). 



The rostrum is straight, or rises sliglitly from the base to the apex, and scarcely 

 reaches the end of the antennular peduncles, while posteriorly it does not extend behind 



the middle of the carapace ; the dental formula is -^, the lower margin witli long cilia, 



and the fir.st upper tooth separated by a wide interval from the second. The antennular 

 flagella are very short, being scarcely as long as the two terminal joints of the peduncle. 

 The entire surface of the body is pubescent. The eyes are of larger size than usual. 

 The last four abdominal segments are cariuatcd, and the distal half of the telson is 

 armed witli well-developed lateral spiniis. The petasma in the male is asymmetrical. 

 The largest Martaban example is (55 mm. long. 



Distribution. Red Sea [Miers) ; Mauritius [Itichtcvs) ; Singapore ( JFalker) ; Malay 

 Archipelago (^a/e) ; N. Australia (i>rt/6') ; W. Australia (.l//er6") ; Loo-choo \'&. [Stinip- 

 son); .Japaa [Stimpson, Bate, Ortinann); Sandwich Is. [Dana). It oc(!urs also in the 

 Atlantic region, on the coast of Senegainbia [Miers), and iu the West Indies is repre- 

 sented by tlie closely allied P. pnbescens, Stin., which Miers regarded as scarcely 

 distinct. 



* .UtLough good specific characters arc probably to be obtained from this organ, and from the petasma in the 

 male, 1 have not attempted to dostribe tliom in the other species, owing to the diflSculty of doing so without 

 rcl'ereuce to tigures. 



